Valve docking devices, systems and methods

ABSTRACT

Various systems, devices and methods associated with the placement of a dock or anchor for a prosthetic valve. The anchor can take the form of an anchor having multiple coils. The distal end portion of the anchor can be spaced radially outwardly from the next adjacent coil to help direct the anchor around native leaflets of a native valve. Various methods include different procedures for delivering the anchor and prosthetic valve.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.14/372,953, which is a Section 371 national phase of PCT PatentApplication Serial No. PCT/IB2013/000593, filed Jan. 31, 2013, whichclaims the benefit of each of U.S. Provisional Application Ser. No.61/796,964, filed Nov. 26, 2012; 61/744,468, filed Sep. 27, 2012;61/687,898, filed May 3, 2012; and 61/592,796, filed Jan. 31, 2012. Thefull disclosures of all of the foregoing are incorporated by referenceherein.

TECHNICAL FIELD

The present invention generally relates to medical procedures anddevices pertaining to heart valves such as replacement techniques andapparatus. More specifically, the invention relates to the replacementof heart valves having various malformations and dysfunctions.

BACKGROUND

Complications of the mitral valve, which controls the flow of blood fromthe left atrium into the left ventricle of the human heart, have beenknown to cause fatal heart failure. In the developed world, one of themost common forms of valvular heart disease is mitral valve leak, alsoknown as mitral regurgitation, which is characterized by the abnormalleaking of blood from the left ventricle through the mitral valve andback into the left atrium. This occurs most commonly due to ischemicheart disease when the leaflets of the mitral valve no longer meet orclose properly after multiple infarctions, idiopathic and hypertensivecardiomyopathies where the left ventricle enlarges, and with leaflet andchordal abnormalities, such as those caused by a degenerative disease.

In addition to mitral regurgitation, mitral narrowing or stenosis ismost frequently the result of rheumatic disease. While this has beenvirtually eliminated in developed countries, it is still common whereliving standards are not as high.

Similar to complications of the mitral valve are complications of theaortic valve, which controls the flow of blood from the left ventricleinto the aorta. For example, many older patients develop aortic valvestenosis. Historically, the traditional treatment had been valvereplacement by a large open heart procedure. The procedure takes aconsiderable amount of time for recovery since it is so highly invasive.Fortunately, in the last decade great advances have been made inreplacing this open heart surgery procedure with a catheter procedurethat can be performed quickly without surgical incisions or the need fora heart-lung machine to support the circulation while the heart isstopped. Using catheters, valves are mounted on stents or stent-likestructures, which are compressed and delivered through blood vessels tothe heart. The stents are then expanded and the valves begin tofunction. The diseased valve is not removed, but instead it is crushedor deformed by the stent which contains the new valve. The deformedtissue serves to help anchor the new prosthetic valve.

Delivery of the valves can be accomplished from arteries which can beeasily accessed in a patient. Most commonly this is done from the groinwhere the femoral and iliac arteries can be cannulated. The shoulderregion is also used, where the subclavian and axillary arteries can alsobe accessed. Recovery from this procedure is remarkably quick.

Not all patients can be served with a pure catheter procedure. In somecases the arteries are too small to allow passage of catheters to theheart, or the arteries are too diseased or tortuous. In these cases,surgeons can make a small chest incision (thoractomy) and then placethese catheter-based devices directly into the heart. Typically, a pursestring suture is made in the apex of the left ventricle and the deliverysystem is place through the apex of the heart. The valve is thendelivered into its final position. These delivery systems can also beused to access the aortic valve from the aorta itself. Some surgeonsintroduce the aortic valve delivery system directly in the aorta at thetime of open surgery. The valves vary considerably. There is a mountingstructure that is often a form of stent. Prosthetic leaflets are carriedinside the stent on mounting and retention structure. Typically, theseleaflets are made from biologic material that is used in traditionalsurgical valves. The valve can be actual heart valve tissue from ananimal or more often the leaflets are made from pericardial tissue fromcows, pigs or horses. These leaflets are treated to reduce theirimmunogenicity and improve their durability. Many tissue processingtechniques have been developed for this purpose. In the futurebiologically engineered tissue may be used or polymers or othernon-biologic materials may be used for valve leaflets. All of these canbe incorporated into the inventions described in this disclosure.

There are in fact more patients with mitral valve disease than aorticvalve disease. In the course of the last decade many companies have beensuccessful in creating catheter or minimally invasive implantable aorticvalves, but implantation of a mitral valve is more difficult and to datethere has been no good solution. Patients would be benefited byimplanting a device by a surgical procedure employing a small incisionor by a catheter implantation such as from the groin. From the patient'spoint of view, the catheter procedure is very attractive. At this timethere is no commercially available way to replace the mitral valve witha catheter procedure. Many patients who require mitral valve replacementare elderly and an open heart procedure is painful, risky and takes timefor recovery. Some patients are not even candidates for surgery due toadvanced age and frailty. Therefore, there exists a particular need fora remotely placed mitral valve replacement device.

While previously it was thought that mitral valve replacement ratherthan valve repair was associated with a more negative long termprognosis for patients with mitral valve disease, this belief has comeinto question. It is now believed that the outcome for patients withmitral valve leak or regurgitation is almost equal whether the valve isrepaired or replaced. Furthermore, the durability of a mitral valvesurgical repair is now under question. Many patients, who have undergonerepair, redevelop a leak over several years. As many of these areelderly, a repeat intervention in an older patient is not welcomed bythe patient or the physicians.

The most prominent obstacle for catheter mitral valve replacement isretaining the valve in position. The mitral valve is subject to a largecyclic load. The pressure in the left ventricle is close to zero beforecontraction and then rises to the systolic pressure (or higher if thereis aortic stenosis) and this can be very high if the patient hassystolic hypertension. Often the load on the valve is 150 mmHg or more.Since the heart is moving as it beats, the movement and the load cancombine to dislodge a valve. Also the movement and rhythmic load canfatigue materials leading to fractures of the materials. Thus, there isa major problem associated with anchoring a valve.

Another problem with creating a catheter delivered mitral valvereplacement is size. The implant must have strong retention and leakavoidance features and it must contain a valve. Separate prostheses maycontribute to solving this problem, by placing an anchor or dock firstand then implanting the valve second. However, in this situation thepatient must remain stable between implantation of the anchor or dockand implantation of the valve. If the patient's native mitral valve isrendered non-functional by the anchor or dock, then the patient mayquickly become unstable and the operator may be forced to hastilyimplant the new valve or possibly stabilize the patient by removing theanchor or dock and abandoning the procedure.

Another problem with mitral replacement is leak around the valve, orparavalvular leak. If a good seal is not established around the valve,blood can leak back into the left atrium. This places extra load on theheart and can damage the blood as it travels in jets through sites ofleaks. Hemolysis or breakdown of red blood cells is a frequentcomplication if this occurs. Paravalvular leak was one of the commonproblems encountered when the aortic valve was first implanted on acatheter. During surgical replacement, a surgeon has a major advantagewhen replacing the valve as he or she can see a gap outside the valvesuture line and prevent or repair it. With catheter insertion, this isnot possible. Furthermore, large leaks may reduce a patient's survivaland may cause symptoms that restrict mobility and make the patientuncomfortable (e.g. short of breathe, edematous, fatigued). Therefore,devices, systems, and methods which relate to mitral valve replacementshould also incorporate means to prevent and repair leaks around thereplacement valve.

A patient's mitral valve annulus can also be quite large. When companiesdevelop surgical replacement valves, this problem is solved byrestricting the number of sizes of the actual valve produced and thenadding more fabric cuff around the margin of the valve to increase thevalve size. For example, a patient may have a 45 mm valve annulus. Inthis case, the actual prosthetic valve diameter may be 30 mm and thedifference is made up by adding a larger band of fabric cuff materialaround the prosthetic valve. However, in catheter procedures, addingmore material to a prosthetic valve is problematic since the materialmust be condensed and retained by small delivery systems. Often thismethod is very difficult and impractical, so alternative solutions arenecessary.

Since numerous valves have been developed for the aortic position, it isdesirable to avoid repeating valve development and to take advantage ofexisting valves. These valves have been very expensive to develop andbring to market, so extending their application can save considerableamounts of time and money. It would be useful then to create a mitralanchor or docking station for such a valve. An existing valve developedfor the aortic position, perhaps with some modification, could then beimplanted in the docking station. Some previously developed valves mayfit well with no modification, such as the Edwards Sapien™ valve.Others, such as the Corevalve™ may be implantable but require somemodification for an optimal engagement with the anchor and fit insidethe heart.

A number of further complications may arise from a poorly retained orpoorly positioned mitral valve replacement prosthesis. Namely, a valvecan be dislodged into the atrium or ventricle, which could be fatal fora patient. Prior prosthetic anchors have reduced the risk ofdislodgement by puncturing tissue to retain the prosthesis. However,this is a risky maneuver since the penetration must be accomplished by asharp object at a long distance, leading to a risk of perforation of theheart and patient injury.

Orientation of the mitral prosthesis is also important. The valve mustallow blood to flow easily from the atrium to the ventricle. Aprosthesis that enters at an angle may lead to poor flow, obstruction ofthe flow by the wall of the heart or a leaflet and a poor hemodynamicresult. Repeated contraction against the ventricular wall can also leadto rupture of the back wall of the heart and sudden death of thepatient.

With surgical mitral valve repair or replacement, sometimes the anteriorleaflet of the mitral valve leaflet is pushed into the area of the leftventricular outflow and this leads to poor left ventricular emptying.This syndrome is known as left ventricular tract outflow obstruction.The replacement valve itself can cause left ventricular outflow tractobstruction if it is situated close to the aortic valve.

Yet another obstacle faced when implanting a replacement mitral valve isthe need for the patient's native mitral valve to continue to functionregularly during placement of the prosthesis so that the patient canremain stable without the need for a heart-lung machine to supportcirculation.

In addition, it is desirable to provide devices and methods that can beutilized in a variety of implantation approaches. Depending on aparticular patient's anatomy and clinical situation, a medicalprofessional may wish to make a determination regarding the optimalmethod of implantation, such as inserting a replacement valve directlyinto the heart in an open procedure (open heart surgery or a minimallyinvasive surgery) or inserting a replacement valve from veins and viaarteries in a closed procedure (such as a catheter-based implantation).It is preferable to allow a medical professional a plurality ofimplantation options to choose from. For example, a medical professionalmay wish to insert a replacement valve either from the ventricle or fromthe atrial side of the mitral valve.

Therefore, the present invention provides devices and methods thataddress these and other challenges in the art.

SUMMARY

The present invention provides a docking station which is stabilized andcapable of retaining a mitral valve replacement prosthesis forcontrolling the flow of blood from the left atrium into the leftventricle. Other devices and methods are provided to improve thepositioning of such a combination during a non-invasive procedure orminimally invasive procedure. Additional devices and methods are alsoprovided to prevent further regurgitation or leaking of blood, such asleakage either through the commisures of the native mitral valve oraround the outer surface of the replacement valve prosthesis.

In one aspect, the invention provides a system for docking a mitralvalve prosthesis. The system comprises a coil guide catheter and ahelical anchor. The coil guide catheter includes a stem portion and adistal portion connected to the stem portion at a first curved portion.The distal portion includes a second curved portion configured togenerally follow the curvature of the mitral valve annulus. The helicalanchor is adapted to be received in and extruded, or otherwise deliveredfrom the coil guide catheter. The helical anchor is formed as multiplecoils having a preformed, coiled configuration after being extruded fromthe coil guide catheter. The helical anchor may be delivered from thecoil guide catheter in other manners instead, but extrusion allows thecoils to gradually and accurately be placed into the proper and desiredposition relative to the native mitral valve. Also, if the operator isnot satisfied with the positioning that is being obtained, the helicalanchor may be moved back into the coil guide catheter and the placementprocedure may be started again. The helical anchor is adapted to supporta prosthetic mitral valve upon being fully extruded or delivered fromthe coil guide catheter and implanted with coil portions above and belowthe mitral valve annulus. The system can further comprise variouscomponents. A prosthetic valve is provided and capable of beingdelivered to the mitral valve position of the patient and expandedinside the multiple coils and into engagement with leaflets of themitral valve. The prosthetic valve may include grooves configured toengage with the multiple coils for coupling the prosthetic valve withthe helical anchor. The helical anchor may further comprise a shapememory material. The multiple coils may include an end coil portion,such as a tail-like extension, formed as an enlarged diameter coilrelative to the next adjacent coil. The extension may take other formsas well. The coils of the helical anchor may take on many differentshapes and forms, some of which are shown herein. The coils may be inseparate planes such as a coil spring, or some or all coils may, atleast initially before implantation, be generally in the same plane. Theend coil portion is configured to engage the left atrial wall of theheart when the multiple coils have been fully delivered from the coilguide catheter with the coil portions positioned above and below themitral valve annulus.

The system may further comprise a plurality of anchoring arms coupledwith the helical anchor and configured to engage the mitral valveleaflets. The anchoring arms may have various configurations, such ashook-like members. A control element may be provided in the system andincludes a connecting element configured to coupled directly orindirectly with the helical anchor for guiding the placement of thehelical anchor relative to the mitral valve. The control element maytake various forms, such as a snare catheter or a catheter including agrasping tool, or simply a cable or suture and the like. The helicalanchor may further include an engagement element configured to allowcoupling of the connecting element therewith. This engagement elementmay also take various forms, such as an enlarged tip or end of thehelical anchor.

The system may further comprise a positioning helix configured to beextruded or otherwise delivered from the coil guide catheter forassisting with positioning of the helical anchor. An extension may becoupled with the second curved portion of the coil guide catheter andconfigured to assist with positioning of the second curved portion ontop of the mitral valve as the helical anchor is being delivered. Theextension may comprise various forms, such as including a flat membranefor engagement with the top of the mitral valve. The system may furthercomprise an anchor delivery catheter and an anchor. The anchor deliverycatheter is, for example, coupled with the coil guide catheter and/orthe helical anchor for delivering the anchor into tissue at the mitralvalve position. Multiple anchors may be delivered, for example, forplicating the annulus tissue and/or closing gaps at the commisures ofthe native mitral valve.

The helical anchor may, for example, comprise a solid wire or a hollowwire configured to be delivered over a guidewire.

In another illustrative embodiment, the invention provides a device fordocking a mitral valve prosthesis comprising an expandable stent and aplurality of anchoring arms. The expandable stent is configured to bedelivered from a catheter to the mitral valve position of a patient andthen expanded. The expandable stent includes an upper end and a lowerend. The plurality of anchoring arms are coupled with the lower end andare configured to engage the mitral valve leaflets. The anchoring armsmay comprise various configurations, such as hook-like members. Invarious embodiments, the hook-like members or other configurations ofanchoring arms may change in dimension as the stent is expanded. Theexpandable stent may further comprise an expandable atrial portion andan expandable valve retaining portion. The expandable atrial portion isconfigured to engage the left atrial wall when expanded at the mitralposition in the heart. The valve retaining portion is adapted to engagethe mitral valve leaflets. The anchoring arms are coupled with the valveretaining portion.

The invention also provides various methods and additional devices,systems and components for performing such methods associated withdocking a mitral valve prosthesis at the mitral position in the heart.For example, various methods and systems allow a prosthetic mitral valveanchor or docking device to be implanted without requiring the operatorto turn a catheter, but rather allowing the operator to use pushingand/or pulling motions that are easier during catheter-basedpercutaneous procedures. The leading tip of the multiple coiled helicalanchor may be directed to an opposite side of the native mitral valvefrom the coil guide catheter. Control elements, such as snare cathetersor catheters with grasping elements may be used to assist with directingthe position of the helical anchor during delivery to the mitral valveposition. Another method involves the placement of the multiple coiledhelical anchor such that a portion of the helical anchor is positionedbeneath the native mitral valve and another portion is placed above thenative mitral valve but not in contact with valve tissue, but ratherengage against only atrial tissue. The lower portion of the helicalanchor may be engaged and pressed against the native mitral leaflets.The helical anchor may have coils with various diameters, and one ormore segments of the coils may be configured to abut or engage againstthe atrial wall for stabilization of the helical anchor and, ultimately,a prosthetic mitral valve.

In more specific terms, the invention, for example, provides a method ofimplanting a mitral valve prosthesis in the heart of a patientcomprising directing a coil guide catheter to the mitral valve positionwithin the heart of the patient. A preformed, curved portion generallyin the plane of the mitral valve is placed in the left atrium with acurvature of the preformed, curved portion generally following a curveof the mitral valve annulus. This preformed, curved portion may take onits curved shape as it is extruded or extended from the coil guidecatheter, or may be activated to the preformed, curved shape after or asit is inserted into position at the mitral valve position. A helicalanchor is delivered in the form of multiple coils from the coil guidecatheter such that a portion of the helical anchor is above the nativemitral valve and a portion is below the mitral valve. A mitral valveprosthesis is implanted within the multiple coils of the helical anchorsuch that the mitral valve prosthesis is supported by the helicalanchor.

In further aspects, for example, an introducer is directed through hearttissue and the coil guide catheter is directed through the introducer tothe mitral valve position. Alternatively, the method may be performedpercutaneously by directing the coil guide catheter through the venoussystem of the patient to the mitral valve position. A control elementmay be used to guide the helical anchor into a desired position relativeto the native mitral valve. The control element may take any suitableform, such as any element that suitably couples (either directly orindirectly) with a portion of the helical anchor. For example, thecontrol element may be directly coupled to the helical anchor, such asby a grasping tool or a suture, or a control element may be coupled withthe coil guide catheter. The control element is used to push and/or pullthe helical anchor into position relative to the native mitral valve.The tip of the helical anchor may be extruded or otherwise deliveredbetween and above the leaflets of the native mitral valve at one of thecommisures and then further directed below the mitral valve into theleft ventricle of the patient. Alternatively, the tip of the helicalanchor may be initially delivered within the left ventricle andsubsequently delivered into the left atrium, such as by directing itbetween the leaflets. Fabric may be placed between the mitral valveprosthesis and a portion of the helical anchor. A guidewire may be usedfor reference purposes. For example, the guidewire may be placed throughthe aortic valve and into the aorta. The guidewire may then be used as areference to assist with positioning the helical anchor.

In additional aspects, a tissue anchor delivering catheter may be guidedto the mitral valve position using the helical anchor and/or the coilguide catheter. A first tissue anchor is delivered into tissue at themitral valve position using the tissue anchor delivery catheter. Asecond tissue anchor may then be delivered into tissue at the mitralvalve position and the first and second tissue anchors may then besecured together to plicate or approximate the tissue.

The mitral valve prosthesis is delivered to a location within thehelical anchor and the mitral valve prosthesis is initially in anunexpanded condition during delivery through a suitable catheter. Themitral valve prosthesis is then expanded such that the mitral valveprosthesis is supported by multiple coils. When the mitral valveprosthesis is expanded, the prosthesis expands against the native mitralleaflets and the leaflets are secured between the prosthesis and theventricular coils or other anchoring structure such that the leafletsare firmly secured. This serves to prevent obstruction of the aorticvalve by the anterior leaflet in addition to providing valve prosthesissupport.

In another general method, a mitral valve prosthesis is implanted in theheart of a patient by directing a stent delivery catheter to the mitralvalve position within the heart of the patient. A stent dock is extendedfrom the stent delivery catheter. An atrial portion of the stent dock isexpanded in the left atrium such that the atrial portion engages thewall of the left atrium. A valve retaining portion of the stent dock isexpanded against the leaflets of the native mitral valve. The mitralvalve prosthesis is implanted within the valve retaining portion suchthat the mitral valve prosthesis is supported by the stent dock.

In further aspects, various helical anchors are provided in desirableembodiments for docking a mitral valve prosthesis. In one embodiment,the anchor comprises a plurality of coils having a preformed, coiledconfiguration after being delivered from the coil guide catheter andadapted to support the prosthetic mitral valve upon being fullydelivered from the coil guide catheter and implanted with respectivecoil portions above and below the mitral valve annulus. In one aspect,the helical anchor includes a distal end portion and the distal endportion is formed to extended downward and radially outward relative toa next adjacent coil such that the distal end portion is spaced from thenext adjacent coil and is configured to be delivered between thecommisures of the native mitral valve.

In another aspect, the helical anchor comprises an upper, atrial coiladapted to be placed above the native mitral valve annulus and a lower,ventricular coil adapted to be placed below the mitral valve annulus.The upper coil is adjacent the lower coil and a gap is formed betweenthe upper and lower coils creating a space that exists prior toimplantation of the coils such that the upper and lower coils do nottrap mitral leaflet tissue upon implantation. This, for example, canallow the native mitral valve tissue to naturally close at thecommisures and prevent blood leakage at those locations. The upper coilmay be of larger diameter than the lower coil so as to engage the atrialwall of the heart upon implantation.

In another aspect, the plurality of coils include an upper, atrial coiladapted to be placed above the native mitral valve annulus and a lower,ventricular coil adapted to be placed below the native mitral valveannulus. In this aspect, an extension extends out of a plane of theupper coil and is spaced from the upper coil so as to engage the wall ofthe atrium and provide stabilization upon implantation in the heart.

In another aspect, the plurality of coils include a plurality of upper,atrial coils and a plurality of lower, ventricular coils. The upper,atrial coils are adapted to be placed above the native mitral valveannulus and extend upwardly to adjustably position the mitral valveprosthesis at a desired height relative to the mitral valve annulus.This can allow the operator to position the mitral valve prosthesis at aheight that, for example, does not obstruct the outflow of blood fromthe ventricle through the aortic valve. The plurality of lower,ventricle coils may be configured to contain the mitral valve leafletstherein and also prevent obstruction of the aortic valve by the anteriormitral leaflet.

Various additional advantages, methods, devices, systems and featureswill become more readily apparent to those of ordinary skill in the artupon review of the following detailed description of the illustrativeembodiments taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1F illustrate in perspective the placement of one embodiment ofa helical anchor in the mitral position of a heart, which is shown inpartial cross section.

FIG. 1G is a cross sectional view of the helical anchor shown in FIG.1F.

FIG. 1H is a cross sectional view of a valve prosthesis retained by thehelical anchor shown in FIGS. 1F and 1G.

FIG. 1i is a cross sectional view of an alternative embodiment of ahelical anchor that has been placed in the mitral position of a heart,wherein the coils located in the atrium do not contact the valveleaflets but anchor against the wall of the atrium.

FIG. 1J is a cross sectional view of a valve prosthesis retained by thehelical anchor shown in FIG. 1I.

FIG. 1K is a cross sectional view of a valve prosthesis retained byanother alternative embodiment of a helical anchor that has been placedin the mitral position of a heart.

FIG. 2 is a perspective view of another alternative helical anchor for amitral valve prosthesis, characterized by an initial area extendingoutward from the coil.

FIG. 3 is a side view of the helical anchor shown in FIG. 2.

FIG. 4 is a bottom view of the helical anchor shown in FIGS. 2 and 3.

FIG. 5 is an aerial view of a helical anchor that has been placed in themitral position of a heart via a commisure in the native mitral valve.

FIG. 6 is a perspective view of another alternative helical anchor of amitral valve prosthesis, characterized by no taper but having a slightoutward turn at the start.

FIG. 7 is a perspective view of another alternative helical anchorhaving a wide tail portion or extension capable of engaging the atrialwall.

FIG. 8 is a perspective view of another alternative helical anchorhaving a tail portion or extension that is substantially wider than thetail portion of FIG. 7, shown placed in the mitral position of a heart.

FIGS. 9A-9C illustrate in perspective an alternative helical anchorhaving anchoring arms and expanding from a compressed state within asheath to a deployed state.

FIG. 10A is a perspective view of the helical anchor of FIG. 9A retainedwithin a sheath and being placed in the mitral position of a heart,which is shown in partial cross section.

FIG. 10B is a cross sectional view of the helical anchor of FIGS. 9A-10Aplaced in the mitral position of heart showing the anchoring armsengaging the valve leaflets.

FIG. 10C is a cross sectional view of a valve prosthesis retained by thehelical anchor of FIGS. 9A-10C.

FIGS. 11A-11C are side views of the helical anchor of FIGS. 9A-9C,showing the anchoring arms expanding from a compressed state to adeployed state (most anchoring arms removed for clarity).

FIG. 12A is a side view of one embodiment of a stent docking havinghooks which are lifted as the stent docking expands and shortens.

FIG. 12B is a side view of another embodiment of a stent docking havingdouble-wire hooks which are lifted as the stent docking expands andshortens.

FIGS. 13A and 13B are side views of hooks spread along a serpentinewire, which are lifted upward as the wire is straightened and which canbe incorporated in a stent docking.

FIGS. 14A and 14B are side views of a serpentine wire mounted on acentral retaining wire and hooks spread along the serpentine wire, whichare lifted upward as the serpentine wire is straightened and which canbe incorporated in a helical anchor.

FIGS. 14C and 14D are cross sectional views of hooks shaped on a wirethat is placed within a sheath and which are lifted upward as the wireis pulled through the sheath.

FIGS. 15A-15E illustrate in perspective the placement of one embodimentof a stent docking in the mitral position of a heart, which is shown inpartial cross section.

FIG. 15F is a cross sectional view of the stent docking of FIG. 15E asit engages with the valve leaflets and atrial wall.

FIG. 15G is a cross sectional view of a valve prosthesis retained by thestent docking shown in FIG. 15F.

FIGS. 16A and 16B illustrate in perspective a stent docking having anatrial component transitioning from a closed state to an open state.

FIG. 16C is a perspective view of the stent docking of FIGS. 16A and 16Bas the valve retaining portion expands and the hooks deploy.

FIG. 16D is a cross sectional view of the fully deployed stent dockingof FIGS. 16A-16C with the valve retaining portion expanded.

FIGS. 17A-17D illustrate in perspective an alternative procedure ofplacing a helical anchor by way of the venous system in the mitralposition of a heart, which is shown in cross section.

FIGS. 18A-18C illustrate in perspective another alternative procedure ofplacing a helical anchor by way of the venous system in the mitralposition of a heart, which is shown in cross section.

FIGS. 19A-19D illustrate in perspective an alternative procedure ofplacing a stent docking by way of the venous system in the mitralposition of a heart, which is shown in cross section.

FIG. 19E is a cross sectional view of an alternative embodiment of thepresent invention, wherein a valve prosthesis is integrated into thevalve retaining portion of a stent docking and is placed in the mitralposition of a heart, shown in partial cross section.

FIG. 20 illustrates in perspective the placement of an embodiment of ahelical anchor in the mitral position of a heart, which is shown inpartial cross section, where the helical portion of the anchor isdeployed and the anchoring loops are retained within a sheath.

FIG. 21 is a close-up view of the helical anchor of FIG. 20 placed inthe mitral position of a heart, which is shown in partial cross section,where the sheath has been retracted to deploy the helical portion in theatrium and the anchoring loops in the ventricle.

FIG. 22 is a cross sectional view of a valve prosthesis retained by thehelical anchor of FIGS. 20-21 with the assistance of a cuff.

FIGS. 23A-23D illustrate in perspective the placement of an embodimentof a helical anchor in the mitral position of a heart, which is shown inpartial cross section, with the assistance of a guidewire placed withinthe right atrium and a positioning helix placed within the left atriumvia the left ventricle.

FIGS. 24A-24C illustrate in perspective the placement of an embodimentof a helical anchor in the mitral position of a heart, which is shown incross section, with the assistance of a positioning helix placed withinthe left atrium via a transseptal delivery.

FIGS. 25A-25C illustrate in perspective the placement of an embodimentof a helical anchor in the mitral position of a heart, which is shown inpartial cross section, with the assistance of a drawstring to draw acoil delivery catheter or coil guide catheter under a leaflet of thenative mitral valve.

FIGS. 26A-26C illustrate in perspective the placement of an embodimentof a helical anchor in the mitral position of a heart, which is shown inpartial cross section, with the assistance of a snare to draw thehelical anchor under a leaflet of the native mitral valve.

FIG. 27A is a close-up view of the coil delivery catheter or coil guidecatheter shown in FIGS. 26A-26C.

FIG. 27B illustrates the coil delivery catheter or coil guide catheterof FIG. 27A having a tip which is deflected downward.

FIGS. 28A and 28B illustrate in perspective the placement of anembodiment of a helical anchor in the mitral position of a heart, whichis shown in partial cross section, with the assistance of a guidewireextending from the left atrium into the left ventricle under the nativemitral valve leaflets.

FIGS. 29A-29C illustrate in perspective the placement of an embodimentof a helical anchor in the mitral position of a heart, which is shown inpartial cross section, with the assistance of a grasping tool to drawthe helical anchor under a leaflet of the native mitral valve.

FIG. 30A is a close-up view of the grasping tool of FIGS. 29A-29C, shownwith jaws closed to hold the end of the helical anchor.

FIG. 30B is a close-up view of the grasping tool of FIGS. 29A-29C, shownwith jaws open to release the end of the helical anchor.

FIGS. 31A-31D illustrate in perspective the placement of an embodimentof a helical anchor in the mitral position of a heart, which is shown inpartial cross section, with the assistance of a grasping tool to centerthe system relative to the native mitral valve and draw the helicalanchor under a leaflet of the mitral valve.

FIG. 32A is a perspective view of one embodiment of a coil deliverycatheter or coil guide catheter having a terminal end shaped such thatwhen the stem of the catheter is placed within a first commisure of themitral valve of a heart, shown in partial cross section, the tip of theterminal end is located at a position substantially close to a secondcommisure of the mitral valve.

FIG. 32B is a top view of the coil delivery catheter or coil guidecatheter of FIG. 32A showing that the U-shaped portion of the coildelivery catheter or coil guide catheter tracks the annulus of themitral valve.

FIG. 32C illustrates in perspective a grasping tool inserted into theatrium to attach to a helical anchor proximal to its tip as the anchoris extruded from the coil delivery catheter or coil guide catheter ofFIG. 32A.

FIG. 32D is a close-up view of the grasping tool of FIG. 32C as itattaches to a helical anchor proximal to its tip.

FIG. 32E illustrates in perspective the system of FIG. 32E, where thegrasping tool has been attached to the helical anchor and is being usedto guide the helical anchor as the anchor is being extruded from thecoil delivery catheter or coil guide catheter.

FIG. 33 is a perspective view of an alternative embodiment of a coildelivery catheter or coil guide catheter having a sail-like extensionwhich sits on the wall of the left atrium, shown in cross section.

FIG. 33A shows the coil delivery catheter or coil guide catheter andsail-like extension of FIG. 33 in cross section.

FIG. 34A illustrates in perspective a system in accordance with thepresent invention in which a snare catheter is attached near the end ofa helical anchor extending from a coil delivery catheter or coil guidecatheter into the atrium of a heart, shown in partial cross section.

FIG. 34B is a top view of the system of FIG. 34A, showing that themitral valve annulus is substantially larger than the U-shaped portionof the coil delivery catheter or coil guide catheter.

FIG. 34C is a perspective view of the system of FIG. 34A, showing theplacement of an anchor between the mitral valve leaflets at a commisurevia the snare catheter.

FIG. 34D is a top view of the system of FIG. 34A, showing the placementof anchors through both the anterior and posterior mitral valve leafletsvia the snare catheter.

FIG. 34E illustrates in perspective the system of FIGS. 34A-34D showingthe placement of a tissue anchor through tissue, such as the mitralvalve leaflet at a second commisure via an tissue anchor deliverycatheter after the first commisure has been plicated.

FIG. 34F is a top view of the system of FIGS. 34A-34E, showing thecompleted plications at both commisures.

FIG. 34G is a cross sectional view of a plication as shown in FIG. 34F.

FIG. 34H is a cross sectional view of a prosthetic mitral valve with ahelically grooved surface that is designed to engage with the coils of ahelical anchor which has been placed in the mitral position of a heart.

FIG. 34I is a cross sectional view of the grooves of the prostheticmitral valve engaged with the coils of the helical anchor.

FIG. 34J is a cross sectional view of an alternative helical anchorplaced in the mitral position of a heart such that the coils of theanchor placed below the mitral leaflets press or are biased upwardagainst the leaflets.

FIG. 34K is a top view of the helical anchor of FIG. 34J showing thecoil of the anchor placed above the mitral leaflets compressing againstthe atrial wall while the coils of the anchor placed below the mitralleaflets press upward against the leaflets to close the commisures.

FIG. 34L is a cross section taken along line 34L-34L of FIG. 34K.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

Referring first to FIGS. 1A-1F, a device, system and method forpositioning a helical anchor in the mitral position of a patient's heartare shown. In this series of figures the system is delivered from theapex of the left ventricle. However, it should be appreciated that thesystem can also be used by direct implantation into an open heart fromthe atrium, ventricle or aorta, or implantation can be made fromcatheters delivered into the left atrium or retrograde from the aorticvalve into the left ventricle. Likewise, the system could be introducedin an open chest into the atrium or percutaneously via the apex of theheart.

FIG. 1A shows an introducer 2 inserted into the apex 6 of the leftventricle 10 of a patient's heart 14 by a small thoracotomy, asternotomy, or from below the diaphragm with an upper abdominalincision. One particularly favorable approach is to make a smallincision on the patient's chest near the apex 6 of the left ventricle 10and then through the apex 6 of the heart 14. To prevent blood leakagefrom the apex 6, a standard purse string suture could be used to holdthe introducer 2 in place and close the defect on removal. It is alsopossible to use an occluder device for entry and exit. The aorta 18,aortic valve 22, and right ventricle 26 are shown for illustrativepurposes. A guidewire 30 is advanced from a lumen 34 of the introducer 2through the left ventricle 10 and between the anterior and posteriorleaflets 38, 42 of the native mitral valve 44 such that a portion of theguidewire 30 is positioned in the left atrium 46. Care should be takenwhen advancing the guidewire 30 to avoid entanglement of the guidewire30 with the chordae tendineae 48 or their associated papillary muscles56, 60. A delivery catheter 64 (FIG. 1B) may then be advanced upon theguidewire 30. The lumen 34 of the introducer 2 should be sufficientlylarge to allow entry of the various delivery system components.

In another embodiment, the introducer 2 may incorporate a check valve(not shown) to prevent blood leakage. A large number of such deviceshave been described which often employ one or more duck-bill shapedvalves. The guidewire 30 can be straight or feature a U-shaped tip orany convenient shape to allow entry into the left atrium 46.

As shown in FIG. 1B, a delivery catheter 64 is introduced over theguidewire 30 into the left atrium 46. The delivery catheter 64 allowsthe introduction of a coil guide catheter 68. The coil guide catheter 68has a preformed shape designed to assist in the introduction of ahelical anchor 72, and can be composed of any material and/or designedin any manner that allows it to be activated during use to the preformedshape. It may, for example, be designed such that it can be straightenedand retain its preformed shape upon release. For example, the coil guidecatheter 68 can be formed from a shape memory material such as Nitinol(NiTi) or from a plastic that retains its shape. Also, the coil guidecatheter 68 could be a composite of several layers. For example, it maycomprise a Nitinol tube with a polymeric cover. It could also becomposed of a mesh or weave of Nitinol with or without a cover. Theinterior could also be lined with a friction reducing material, such asa lubricious coating material to make it more smooth and slippery tointroduce the helical anchor 72. The coil guide catheter 68 isstraightened for introduction by the delivery catheter 64, which isrelatively stiff compared to the coil guide catheter 68. Other optionsfor obtaining the preformed shape may include introducing the distal endof the coil guide catheter 68 as a relatively straight element and thenactivating it such that it takes on the desired preformed shape, such aswith one or more curves that will be discussed below and assist withproper introduction and positioning of the helical anchor 72. One suchactivatable design would include small coil segments with bevels that,when pulled together, assume the desired shape. It will be appreciatedby those of skill in the art that the coil guide catheter 68 may bedirected to the mitral valve position without the use of a deliverydevice, such as the delivery catheter 64. For purposes of themaneuvering the coil guide catheter 68 or other catheter devices used inthe embodiments of this invention, any of the various known manners ofdeflecting the distal end may be utilized.

In one embodiment, the coil guide catheter 68 is positioned in the leftatrium 46 or just inside the left ventricle 10 near a mitral valvecommisure 80. It should be noted that commisures 80 are the points wherethe anterior mitral leaflet 38 and posterior mitral leaflet 42 contacteach other to close the mitral valve 44 at the valve perimeter orannulus 84. This position can be confirmed visually if the heart 14 isopen. However, it is preferred to conduct this procedure with a closedand beating heart 14. In this case imaging modalities such asfluoroscopy, X-ray, CT or MR imaging can be used. Echocardiography in 2Dor 3D can also be used to help guide the position. It should beappreciated that the coil guide catheter 68 can also be positioned inthe left ventricle 10 for placement of the helical anchor 72.

When the delivery catheter 64 is removed, the coil guide catheter 68assumes its preformed shape to facilitate the introduction of thehelical anchor 72, as shown in FIG. 1C. The coil guide catheter 68comprises a stem 88 and a U-shaped portion 92. The coil guide catheter68 has a lumen 96 which is roughly circular with a diameter similar tothe helical anchor 72 which it delivers. The U-shaped portion 92 of thecoil guide catheter 68 is oriented generally parallel to the plane ofthe mitral valve 44 and helps to correctly position the depth of thecoil guide catheter 68 inside the heart 14 so that the helical anchor 72is extruded into the plane of the mitral valve 44. This ensures that thehelical anchor 72 will be directed closely under the leaflets 38, 42.The tip 100 of the helical anchor 72 may also have a slight outward anddownward turn to allow direction of the helical anchor 72 under thevalve leaflets 38, 42. The coil guide catheter 68 is shown with a slightupward turn at the stem 88 before the U-shaped portion 92 that sitsparallel to the valve 46. This is not necessary but helps to makepushing the helical anchor 72 into position less difficult. It will alsobe appreciated that the distal portion of the coil guide catheter 68need not be parallel to the valve 44 and annulus 84, as shown. It mayinstead be angled and yet the distal end of the helical anchor 72 willnaturally orient itself downwardly and between the leaflets 38, 42 andthen extrude and coil or spiral into the proper position. It should alsobe noted that in each embodiment herein, no puncturing of valve, leafletor heart tissue needs to take place.

As shown in FIG. 1C, the helical anchor 72 has been advanced so that theend of the helical anchor 72 is starting to track under the posteriorleaflet 42. The tip 100 of the coil guide catheter 68 is located abovethe plane of the valve 46, but it can also be located under theposterior leaflet 42. It should be noted that there is no need forpenetration through any area of tissue. The helical anchor 72 is passedbetween leaflets 38, 42 near a commisure 80. It is appreciated thatpenetration through the leaflets 38, 42 could be used, but is lessdesirable due to the delicate nature of the leaflets 38, 42. It is alsopossible to pass the helical anchor 72 at any location, including alocation that is distal from a commisure 80. This may result in foldingor bending of one or both of the leaflets 38, 42 if the starting pointis not at or near the commisure 80 once the helical anchor 72 is placed.

The helical anchor 72 is further advanced by being pushed through thecoil guide catheter 68. FIG. 1D shows most of a complete revolution ofthe helical anchor 72 positioned under the mitral valve 44. The numberof lower coils 104 of the helical anchor 72 can vary from less than oneto as many as the operator thinks is useful. After the lower coils ofthe anchor 72 have been placed under the mitral valve annulus 84, uppercoils 108 of the helical anchor 72 are positioned above the annulus 84by rotating the coil guide catheter 68 as the helical anchor 72 isadvanced. This is shown in FIG. 1E.

It is also possible to avoid rotation during delivery of the helicalanchor 72 above the mitral valve annulus 84, since the shape memorymaterial will assume the correct position. However, it is understoodthat the helical anchor 72 may jump and put force on the coil guidecatheter 68 if there is no rotation. Another valuable option forinserting the helical anchor 72 without the need for rotation of thecoil guide catheter 68 is to straighten the coil guide catheter 68. Whenthe coil guide catheter 68 has been straightened, the helical anchor 72which has a circular preformed shape will not have to compete with thepreformed shape of the coil guide catheter 68 and can resume itspreformed shape inside the atrium 46.

After the helical anchor 72 is implanted, the coil guide catheter 68 isremoved. FIG. 1F shows that about two coils 108 have been placed abovethe mitral valve annulus 84 and about two coils 104 have been placedbelow the mitral valve annulus 84. In other embodiments, the arrangementshown can be varied. There may be any number of coils 104, 108 as theoperator sees fit. It should be noted that even a portion of a coil104,108 above or below the annulus 84 may be sufficient to retain thehelical anchor 72. It should be noted that the size of the helicalanchor 72 can be preselected before placement so that it closely matchesthe diameter of the annulus 84. This maximizes the size of thereplacement valve implant that can be placed inside the helical anchor72 and helps reduce the risk of a leak at the commisures 80.

The gap between the coils 104, 108 can be adjusted when making thehelical anchor 72. By leaving a slightly larger gap between the coils104, 108 sitting above and below the annulus, it is possible to allowthe valve tissue 44 to close at the commisures 80 by permitting a smallamount of motion of the leaflets 38, 42 as the heart 14 contracts. Thisis one strategy to ensure there is no leak around the helical anchor 72.The coils 104, 108 do not need to trap the leaflet tissue 38, 42. Infact, leaving a gap between the ventricular and atrial coils 104, 108may be advantageous in permitting the leaflet tissue 38, 42 to close atthe commisures 80 and prevent blood flow leakage at these locations. Inaddition to leaving a sufficient gap between at least the coils 104, 108(i.e., a gap that spans the annulus 84 when the anchor 72 is implanted,other manners of preventing the trapping of annulus tissue are possible.For example, the atrial coil or coils 108 may be of larger diameter oreven shaped differently than a “coil” such that it comprises anextension that engages a portion of the atrial wall 46 a above theannulus 84. Various other designs for atrial and/or ventricular anchorstabilization are possible as well.

FIG. 1F shows the coils 104 wrapping around the anterior leaflet 38 ofthe mitral valve 46 which is near the aortic valve 22. The anteriorleaflet 38 is engaged by the lower coils 104 of the helical anchor 72and is thereby restricted from obstructing the flow of blood into theaortic valve 22. The coils 104 can also be adjusted to sit even lowerthan shown if additional control of the anterior mitral leaflet 38 isdesired. In other embodiments, the number of lower coils 104 in thehelical anchor 72 can be adjusted to cover more of the anterior mitralleaflet 38. The lower coils 104 can sit high against the annulus 84, orlower in the ventricle 10.

It should be noted that once a helical anchor 72 has been inserted asdescribed herein, the patient's native mitral valve 44 continues towork, i.e., the leaflets 38, 42 continue to open and close during theheart cycle as required. The valve 44 can open and close normallydespite some restriction of the opening by the coils 104, so thatfunctionally the patient can remain stable. This allows an operator toimplant a valve prosthesis within the anchor 72 without the risk of thepatient being in a position of hemodynamic compromise. Therefore, theprocedure can be performed on a beating heart 14 without a heart-lungmachine. Another feature of this design is that when the replacementvalve (i.e., prosthesis) is positioned, the location of the replacementvalve (e.g. in the annulus, relatively higher than the annulus, or inthe ventricle) can be chosen by the location of the coils 104, 108 andby the physician's decision about the optimal placement of the valveprosthesis. This allows a valve prosthesis or replacement valve implantto sit lower or higher in the annulus 84 depending on the particulardesign of the helical anchor 72 and the patient's anatomy and clinicalsituation.

FIG. 1G shows a helical anchor 72 that has been implanted withapproximately three coils 108 above the mitral valve annulus 84 in theleft atrium 46 and approximately two coils 104 below the annulus 84 inthe left ventricle 10. The anterior and posterior leaflets 38, 42 areengaged by the coils 104, 108 of the helical anchor 72. In particular,the anterior leaflet 38 is restrained by the coils 104, 108 so that itis prevented from obstructing the flow of blood into the aortic valve22. In this embodiment, at least one or more of the coils 104 below theannulus have diameters greater than the diameter of at least one or moreof the coils 108 above the annulus 84. This type of design can have anumber of benefits. For example, it can assist in closing the commisures80 and thereby prevent leakage of blood at these locations after theprocedure is complete. It can also assist with the insertion of thehelical anchor 72 to initially start extruding the larger diametercoil(s) and then proceed with smaller diameter coils. Referring to FIG.1H, the use of smaller diameter coils 108 at the location where a mitralvalve prosthesis 120 will be implanted allows for implantation of asmaller sized prosthesis 120, and this can be advantageous for variousreasons. Some patients may have a large diameter annulus 84 and a doctormay want to implant a smaller prosthesis 120. This will also helpprevent obstruction of the aortic valve 22. The valve prosthesisretention coils 108, e.g. the smaller coils, may also extend higher intothe left atrium 46 such that the prosthesis is also positioned higherand away from the aortic valve 22. It should be appreciated that thecoils 104, 108 of the helical anchor are not required to have the samediameter. Rather, it may be appropriate for the diameter to vary on eachturn or coil 104, 108. Likewise, the coils 104, 108 are not required tobe precisely circular. It may be useful for some embodiments to haveturns in the coils that are more oval or elliptical in shape. Forexample, an elliptical shape may be useful if the coils 108 above theannulus 84 seat against the atrial wall 46 a rather than on the nativemitral valve 44 itself.

Still referring to FIG. 1H, a valve prosthesis 120 is retained by ahelical anchor 72 in the mitral position. The valve prosthesis 120comprises a pair of artificial leaflets 122, 124 mounted within anexpanded stent structure 126. The artificial leaflets 122, 124 maycomprise pliable animal tissue such as cow, pig or horse pericardium oranimal valve tissue. Many variations of percutaneous valves 120 havebeen described for implantation with a catheter, such as those used foraortic valve replacement. The valve prosthesis 120 can be selfexpanding, such as previously described percutaneous valves based on ashape memory stent such as Nitinol (NiTi), or balloon expandable such asa stainless steel or non-shape memory stent material. The valveprosthesis 120 can be introduced through the same introducer 2 initiallyshown in the apex 6 of the left ventricle 10. This portion of theprocedure is well known since thousands of percutaneous valve implantsare performed each year, and all appropriate technologies and methodscan be employed to insert the valve prosthesis 120 and anchor it intothe helical anchor 72 as shown. The helical anchor 72 can be seen onX-ray, MR, CT and echocardiography to help position the valve prosthesis120 and perform the procedure. Radiopaque markers such as gold may beadded to the surface of the shape memory materials to improve X-rayidentification.

In this embodiment, the valve prosthesis 120 is docked to the helicalanchor 72 such that the anterior and posterior leaflet tissue 38, 42 issecured between the anchor 72 and the valve prosthesis 120. This servesto lock the anchor 72 in position and prevent it from moving ordislodging. The leaflet tissue 38, 42 also creates a natural seal toprevent blood flow between the valve prosthesis 120 and helical anchor72. In other embodiments locking of the anchor 72 can also be completedby placing coils 108 of the anchor 72 above the mitral valve 44 suchthat the upper coils 108 do not compress the valve leaflets 38, 42 butinstead abut the atrial wall 46 a.

The replacement valve 120 can be anchored against the coil(s) 108 of theanchor 72 above the annulus 84, below the annulus 84 or both. FIG. 1Hshows a valve 120 that is relatively centered and is anchored againstthe coils 104, 108 about equal amounts above and below the annulus 84.The precise position can be chosen by the operator. Also, the coils 104,108 can be adjusted (more coils 104, 108 on the atrial or ventricularside) to help facilitate locating the valve 120.

In order to prevent movement or slipping of the helical anchor 72, it ishelpful to compress the leaflets 38, 42 between the valve prosthesis 120and at least one part of the helical anchor 72 below the annulus 84. Theinsertion of the valve prosthesis 120 into the helical anchor 72 locksthe anchor 72 in position. An advantage of pressing the valve prosthesis120 against both the coils 104, 108 above and below the valve 44 is thatmotion of the coils 104, 108 will be stopped. The prosthesis 120 willlock any coils 104, 108 it abuts against into a solid and non-movableposition. This can be important because with each heartbeat there ismovement in the heart 14. Nitinol and other shape memory materials arestrong but are known to have limited resistance to cyclic loads, causingthem to fatigue rapidly and fracture. Therefore, preventing movement isvery important.

It should be appreciated that in other embodiments the valve prosthesis120 may not be attached to the helical anchor 72 both above and belowthe annulus 84. The coils 108 above the annulus 84 do not necessarilyneed to abut the valve prosthesis 120. Furthermore, anchoring of thevalve prosthesis 120 can be achieved by only engaging the anterior andposterior leaflets 38, 42 against the coils 104 below the annulus 84.There can be minimal or no coils 108 of the helical anchor 72 above theannulus.

As described previously, the entire procedure can be performed throughthe atrium 46 or via a transseptal puncture. More details of atransseptal procedure will be shown and described below.

It is not necessary to have coils 104, 108 of the helical anchor 72engaged with both sides of the leaflets 38, 42. FIG. 1I shows anembodiment of a helical anchor 72 in accordance with the presentinvention. The anterior and posterior leaflets 38, 42 are engaged by thecoils 104 of the helical anchor 72 below the mitral valve annulus 84 inthe left ventricle 10. In particular, the anterior leaflet 38 isrestrained by the coils 104 so that it is prevented from obstructing theflow of blood into the aortic valve 22. However, the coils 108 on theopposite side of the valve 44 in the left atrium 46 do not contact theleaflets 38, 42 but anchor against the atrial wall 46 a. Thisarrangement keeps the anchor 72 from moving as in previous descriptionsbut relies on the atrial wall 46 a rather than valve leaflets 38, 42 tosupport the upper coils 108. The helical anchor 72 cannot move upwardtoward the atrium 46 due to the contact with the leaflets 38, 42 belowthe valve 44, and it cannot move downward due to the contact with theatrial wall 46 a.

It should be appreciated that combinations of the helical anchorvariations could be used in other embodiments and may be easily made.For example, helical anchors 72 could be constructed such that coils104, 108 sit below the valve 44 and above the valve 44, but there is agap between the coils 104 below the valve 44 and coils 108 above thevalve 44. Valve leaflets 38, 42 would not be trapped between coils 104,108 of the helical anchor 72. This arrangement allows the mitral valve44 to approximate naturally at the commisures 80 because the leaflettissue 38, 42 is not trapped between coils 104, 108 and can preventleaks at the commisures 80. In another embodiment, additional coils 104,108 may be added which would extend from the top of the coils 108previously described in the left atrium 46 to anchor against the atrialwall 46 a. This arrangement may allow a valve prosthesis 120 to befastened to coils 104, 108 above and below the annulus 84 to improve thestability of the valve prosthesis 120 and anchor to the atrial wall 46a. It should be noted that in addition to the gap between coils 104 and108, both the diameter of the helical anchor 72 and shape of the coils104, 108 could be varied. The helical anchor 72 does not need to beuniform in diameter or profile. For example, the coils 108 above theannulus 84 might be made thicker than the coils 104 below the annulus 84for more strength of attachment to the atrial wall 46 a. There could bethicker and thinner areas of the coils 104, 108 as needed for strengthor function. Furthermore, the cross sectional shape of the coils 104,108 does not need to be circular.

FIG. 1J shows a valve prosthesis 120 that has been anchored to thehelical anchor 72 shown in FIG. 1I. In this embodiment, the valveprosthesis 120 comprises a pair of artificial leaflets 122, 124 mountedwithin an expandable stent structure 126. The artificial leaflets 122,124 may comprise pliable animal tissue such as cow, pig or horsepericardium or animal valve tissue. Various suitable valve prostheseshave been previously described. In this embodiment, the valve prosthesis120 is docked to the helical anchor 72 such that the anterior andposterior leaflet tissue 38, 42 is secured between the anchor 72 and thevalve prosthesis 120. This serves to lock the anchor 72 in position andprevent it from moving or dislodging. The leaflet tissue 38, 42 alsocreates a natural seal to prevent blood flow between the valveprosthesis 120 and helical anchor 72.

As described, in other embodiments more coils 108 could be placed abovethe annulus 84 (in addition to the coils 108 which contact the atrialwall 46 a) so that the valve prosthesis 120 could anchor to coils 104,108 of the helical anchor 72 above and below the annulus 84 aspreviously described with reference to FIG. 1H. The coils 108 above theannulus 84 could easily not abut the leaflets 38, 42, but rather therecould be a gap between the coils 108 above and coils 104 below theannulus 84 such that there is no trapping of leaflet tissue 38, 42between coils 104, 108.

FIG. 1K shows an embodiment of a helical anchor 72 having a varied coilconfiguration. The anchor 72 is held in place by coils 108 a extendingabove the annulus 84 which abut against the atrial wall 46 a and bycoils 104 extending below the annulus 84 which abut against theventricular wall 10 a. Additional coils 108 b above the annulus 84engage and hold a valve prosthesis 120 without contacting either of theanterior or posterior leaflets 38, 42. The valve prosthesis 120comprises a pair of artificial leaflets 122, 124 mounted within anexpandable stent structure 126. The artificial leaflets 122, 124 maycomprise pliable animal tissue such as cow, pig or horse pericardium oranimal valve tissue. Various suitable valve prostheses have beenpreviously described. In this embodiment, the coils 104 of the helicalanchor 72 below the annulus 84 may not trap the anterior and posteriorleaflet tissue 38, 42 between the anchor 72 and the valve prosthesis 120sufficiently to create a seal between the helical anchor 72 and valveprosthesis 120 or prevent the anterior leaflet 38 from obstructing bloodflow into the aortic valve 22. Therefore, in another embodiment thecoils 104 below the leaflets 38, 42 may be adjusted to tightly securethe leaflets 38, 42 against the valve prostheses 120, rather thanabutting the ventricular wall 10 a. Securing the anterior leaflet 38,such as in any of the manners described herein can be important forpurposes of preventing obstruction of blood flow from the left ventricle10 through the aortic valve 22. As previously mentioned, coils 108 a and108 b may be configured such that the prosthesis 120 can be implanted ata desired height relative to the annulus 84. In addition to preventingobstruction of the aortic valve 22 with the prosthesis 120, this canprevent the prosthesis from contacting the walls of the left ventricle10, which could lead to rupture of the left ventricle 10. This lattercase can be especially important for patients with small leftventricles.

The helical anchor of the present invention can be constructed in alarge number of variations. FIGS. 2, 3 and 4 show an embodiment of ahelical anchor 130 wherein the lower coils 132, or first approximatelytwo coils, of the anchor 130 have diameters that are greater than thediameter of the remaining upper coils 134. This allows for easyengagement with the mitral annulus 84 (FIG. 1A) during insertion. Inaddition, the lower coils 132 of the anchor 130 extend slightly downwardcreating gaps so that the lower coils 132 do not press against eachother, while the upper coils 134 are shown contacting each other. Thisfeature allows the initial lower coil 132 to slip to the opposite sideof the mitral leaflets 38, 42 as it is inserted and to avoid unwantedfriction or drag as the anchor 130 is pushed into place. Both of thesevariations, whether included together or separately in otherembodiments, may help with anchor placement and improve retention.Further embodiments, not shown, can include anchors having coils ofvarying diameters, coils spaced with varying gap sizes, and coils whichtaper, expand, or flare larger or smaller. It should be noted that thecoils may stretch radially outward when the valve prosthesis 120 (FIG.1H) is placed or expanded within the helical anchor 72 or 130. This isseen particularly in the middle coils. Therefore, even though the coilsmay have different diameters initially, the coils may all contact thevalve prosthesis 120. It should also be noted that a valve prosthesis120 may have a varying diameter, which may be designed for optimalcontact with a desired number of coils of the helical anchor 72 or 130to improve retention.

FIG. 5 illustrates an embodiment of the present invention in which ahelical anchor 140 for docking a valve prosthesis (not shown) passesthrough one of the two commisures 80 of the mitral valve 44. Coils 142,144 of the anchor 140 are located above and below the annulus 84, and aconnecting segment 146 is located across the commisure 80 withoutpassing through valve tissue.

FIG. 6 illustrates another illustrative embodiment of a helical anchor150, wherein the anchor 150 is shaped as a simple helix with no taperand a slight outward turn 152 at one end to facilitate initial turningof the helical anchor 150 under the annulus 84 (FIG. 1A). In addition,gaps 154 are provided between the coils 156 of the anchor 150 to preventunwanted friction or drag as the anchor 150 is pushed into place. Theslight outward turn, or outward extension has a larger radius from thecenter of the anchor 150 than the next adjacent coil. The distal end oroutward turn 152 may also be oriented downward or away from the nextadjacent coil in a direction generally along the central axis of thehelical anchor 150, as shown. In this embodiment, the distal end 152extends radially outward and downward relative to the next adjacent coil154 to create a gap or spacing between end 152 and coil 154 that existsprior to implantation. This design feature also helps avoid tangling orinterference with the chordae tendineae 48 and/or leaflets 38, 42 duringinsertion of the helical anchor 150 and with downsizing needs when asmaller prosthesis 120 is to be implanted.

After a helical anchor has been implanted and prior to a valveprosthesis being fastened therein, the anchor may slip out of positionor dislodge completely. Atrial anchoring features can be added toprevent this unwanted movement. For example, a helical anchor 160 mayinclude a tail-like extension 162 as shown in FIG. 7. The uppermosthelical convolution 162 is of larger diameter than lower coils 164 so asto make contact with or abut the atrial wall 46 a as shown in FIG. 8. Aspreviously described, the coils 164 a of the helical anchor 160 belowthe mitral valve annulus 84 in the left ventricle 10 engage the anteriorand posterior leaflets 38, 42. In particular, the anterior leaflet 38 isrestrained by coils 164 a so that it is prevented from obstructing theflow of blood into the aortic valve 22. By applying a spring forceagainst the atrial wall 46 a, the tail-like extension 162 assists inpreventing the helical anchor 160 from moving. It should be appreciatedthat in other embodiments the tail-like extension 162 may not comprise ahelical shape. For example, the tail-like extension 162 can comprise asimple straight segment passing outward from the helical anchor 160 atan angle of approximately 90 degrees. A wide variety of tail-likeextensions or other atrial anchoring features could be incorporated invarious embodiments. The tail-like extension 162 could eliminateentirely the need for coils 164 b above the valve leaflets 38, 42 toengage the leaflets 38, 42. The coils 164 b above the leaflets 38, 42could be eliminated or the coils 164 b above the leaflets 38, 42 couldbe arranged to produce a gap above the leaflets 38, 42. The gap canallow the helical anchor 160 to have a much longer contact with thevalve prosthesis 120 (FIG. 1H). This can help to orient the valveprosthesis 120 so that it is aimed appropriately into the left ventricle10 and atrium 46. It is important to ensure that the inflow of the valveprosthesis 120 into the ventricle does not abut against the posteriorwall 10 a of the left ventricle 10, as this may cause wear and ruptureof the heart 14, or an impairment of flow into the left ventricle 10.

If an embodiment of the invention incorporates a gap between the upperand lower coils of a helical anchor, as described previously herein,there may be a weak point in the system that is prone to fracture. Thesegment of the helical anchor that connects the coil above the valve 44to that below the valve 44 may move rhythmically with the heart'scontraction and fracture. To prevent this unwanted movement, anchoringthe valve prosthesis 120 to coils both above and below the leaflets 38,42 will lock these two helical coil portions together, preventingrelative motion. Even if a connecting segment between upper and lowercoil portions were to fracture, the valve prosthesis 120 would holdcoils above the leaflets 38, 42 and below the leaflets 38, 42 together,like a splint. This would prevent embolization of parts. It is alsopossible that a connecting segment between upper and lower helices wouldnot be needed after replacement valve implantation. Connection of upperand lower coil portions is necessary only for the insertion of thehelical anchor. The connecting segment between upper and lower coilportions could be purposely made expendable (small and thin) orremovable.

Referring now to FIGS. 9A-9C, an embodiment of the present invention isdepicted wherein a delivery apparatus 180 comprises an external sheath182 and an internal shaft 184 having a converging tip 186. A helicalanchor 190 is placed over the shaft 184 and restrained within the sheath182, shown in dash-dot lines, in order to tighten the coils 192 of theanchor 190 prior to implanting. The converging tip 186 is provided toassist an operator with guiding the apparatus 180 through a patient'svenous system, if used percutaneously, or through the patient's heart.Anchoring arms 194 such as hooks are provided along a coil 192 a of thehelical anchor 190, and are constructed of a shape memory material. Theanchoring arms 194 have two spaced apart wire portions 194 a, 194 b toprovide a strong anchor point to hold tissue. The anchoring arms 194 arerestrained and straightened in a downward orientation within theexternal sheath 182. When the delivery apparatus 180 is removed, thecoils 192 of the anchor 190 are released and spring radially outward totheir natural diameter and the anchoring arms 194 fold in an upwarddirection forming hooks to engage tissue, as shown in FIGS. 9B and 9C.

Referring now to FIGS. 10A-10C and 20-22, in one embodiment of thepresent invention a delivery catheter 200 is inserted into the leftventricle 10 of a patient's heart 14. The delivery catheter 200 includesa lumen 202 which carries a delivery apparatus 180 as previouslydescribed, for example, having an external sheath 182 and a shaft 184with a converging tip 186. A helical anchor 190 having anchoring arms194 is compressed over the shaft 184 and retained by the sheath 182 suchthat the coils 192 of the anchor 190 are tightened. The tip 186 assiststhe advancement of the delivery apparatus 180 between the anterior andposterior leaflets 38, 42 of the mitral valve 44 from the left ventricle10 into the left atrium 46 as shown in FIG. 10A. As the external sheath182 is retracted, the helical anchor 190 springs open to its originalsize as shown in FIGS. 10B and 20. This helical anchor 190, as withother embodiments, may take various forms, such as with differentdiameter coils 192 instead of constant diameter coils, and/or coils thatengage the atrial wall 46 a as opposed to contacting or engaging leaflettissue. For environmental purposes, FIG. 20 shows the right atrium 210,inferior vena cava 212, superior vena cava 214, aortic valve 22, andaorta 18 (in dash-dot lines). As the external sheath 182 is sliddownward relative to the anchor 190, the anchoring arms 194 unfold andexpand, for example, into hooks. The hooks 194 wrap around the anteriorand posterior leaflets 38, 42 and hold the anchor 190 in position, asshown in FIGS. 10B and 21. The anchoring arms, or hooks in thisembodiment, also capture or otherwise secure the leaflets 38, 42 andhelp prevent the anterior leaflet 38 from obstructing blood flow out ofthe left ventricle 10 through the aortic valve 22. It should be notedthat the edges of the valve leaflets 38, 42 are attached to chordaetendineae 48 which extend from papillary muscles 56, 60. In thisembodiment, the hooks 194 are constructed in a shape that is relativelynarrow at the distal ends 194 c in order to pass between the chordaetendineae 48 (see FIGS. 9B and 9C). However, it is appreciated that thehooks 194 may be constructed in a wide variety of shapes withoutdeparting from the scope of the invention. For example, FIG. 21 shows analternative embodiment having hooks 194 that are wide at the distal ends194 c to form loops. The wide-loop hooks 194 of FIG. 21 provide improvedretention of the valve leaflets but may be difficult to position aroundthe chordae tendineae 48. Referring again to FIGS. 10A-10C, a valveprosthesis 120 is positioned and retained within the helical anchor 190as shown in FIGS. 10C and 22. In the embodiments of FIGS. 10C and 22,the valve prosthesis 120 is mounted in a stent 126 and comprises a pairof artificial leaflets 122, 124. The artificial leaflets 122, 124 maycomprise pliable animal tissue such as cow, pig or horse pericardium oranimal valve tissue. The valve prosthesis 120 may be self expanding orballoon expandable. Leaflet tissue 38, 42 is retained by hooks 194toward the valve prosthesis 120, preventing the anterior leaflet 38 fromobstructing blood flow through the aortic valve 22. In the embodimentshown in FIG. 22, a circumferential cuff 220 is inserted between thehelical anchor 190 and the valve prosthesis 120 in order to improveretention of the valve prosthesis 120 in the atrium 46 and to provide aseal between the anchor 190 and the valve prosthesis 120 to preventleakage.

FIGS. 11A-11C illustrate the transition of an anchoring arm 194 from astraightened position (FIG. 11A) to an activated position (FIG. 11C). Asstated previously, the anchoring arm 194 may be constructed of shapememory materials. FIG. 11A shows anchoring arms 194 each having a fixedend 222 and a free end 224 located along a coil 192 a. When theanchoring arm 194 is released from a straightened position (FIG. 10A),the free end 224 may move away from the fixed end 222, causing the baseof the anchoring arm 194 to elongate, and the distal tip 194 c of theanchoring arm 194 may begin to bend or fold upward as shown in FIG. 11B.The anchoring arm 194 is activated when the distal tip 194 c is bent toits original shape forming a hook as shown in FIG. 11C. In anotherembodiment, the anchoring arm 194 may have no fixed end 222, but rathertwo free ends 224 so that it may slide along the helical anchor 194 atboth ends. The number and configuration of anchoring arms 194 providedmay vary.

FIG. 12A shows a stent dock 230 with anchoring arms such as hooks 232 atthe bottom in accordance with another embodiment of the presentinvention. The hooks 232 may be separately attached or integrated intothe construction of the stent dock 230. The midpoint of the stent dock230 is shown as dash-dot line or axis 234. The hooks 232 are attached tothe apex 236 of each lowermost cell 238 of the stent dock 230. Otherembodiments may incorporate double sided hooks (such as shown in FIGS.11A-11C) that are anchored with one base on one cell 238 and one base onanother cell 238. As the stent dock 230 is expanded, the cells 238collapse vertically causing the hooks 232 to rise such as to engageleaflet tissue. In this manner shortening of the stent dock 230 (i.e.,radial expansion thereof) is used in a functional way to activate thehooks 232.

FIG. 12B shows another embodiment of a stent dock 240 as it expands sothat the stent dock 240 shortens and anchoring arms such as double-hooks242 are lifted in a manner similar to that described with reference toFIG. 12A. Additional embodiments may include a wide variety of hooktypes and attachment structure. For example, double-wire hooks may beattached with one wire end at the bottom of a first cell 244 of thestent dock 240, and another wire end at the bottom of an adjacent cell244 of the stent dock 240. This arrangement would cause the base of thehook 242 to lengthen as the stent dock 240 is expanded. In this manner ahook 242 could start to engage tissue with a narrow shape and then widenas the stent dock 240 is expanded. This may be a useful feature when ahook 242 is attached to a valve leaflet between chordae tendineae.

Referring now to FIGS. 13A and 13B, hooks 250 are shown spread along aserpentine wire 252. The turns 254 of the wire 252 separate the hooks250. As the wire 252 is straightened, the hooks 250 spread apart andbecome elevated as shown in FIG. 13B. In this manner the hooks 250 maybe activated to retain tissue.

Similarly, FIGS. 14A and 14B illustrate hooks 250 spread along aserpentine wire 252 which is mounted on a central retaining wire 256.The hooks 250 spread apart and become elevated as the serpentine wire252 is straightened along the central retaining wire 256 as shown inFIG. 14B. The central retaining wire 256 may, for example, comprise ahelical anchor (such as described herein) which carries a serpentinewire 252 thereon.

FIGS. 14C and 14D illustrate yet another method of hook deployment inaccordance with optional aspects of the present invention. A wire 260 isfolded such that a plurality of anchoring arms such as hooks 262 havingV-shaped portions are provided. The wire 260 is placed within an outershell or hollow structure 264 having apertures 266 such that the hooks262 are permitted to extend through the apertures 266 as shown in FIG.14C. As the wire 260 is pulled through the shell 264, V-shaped portions270 retract and straighten within the shell 264 causing the hooks 262 tolift upward as shown in FIG. 14D. There are many other ways to activatea hook associated with the lengthening of a wire, stent dock or helicalanchor in accordance with the inventive principles.

Referring now to FIGS. 15A-15F, a system and method for positioning astent dock 280 in the mitral position or location of a patient's heart14 is shown. FIG. 15A shows an introducer 2 inserted into the apex 6 ofthe left ventricle 10 by a small thoracotomy, a sternotomy, or frombelow the diaphragm with an upper abdominal incision. One particularlyfavorable approach is to make a small incision on the patient's chestnear the apex 6 of the left ventricle 10 and then through the apex 6 ofthe heart 14. To prevent blood leakage from the apex 6, a standard pursestring suture could be used to hold an introducer 2 in place and closethe defect on removal. It is also possible to use an occluder device forentry and exit. A guidewire 30 is advanced such that a portion of theguidewire 30 is positioned in the left atrium 46. Care should be takenwhen advancing the guidewire 30 to avoid entanglement of the guidewire30 with the chordae tendineae 48 or their associated papillary muscles56, 60. A delivery catheter 64 may then be advanced upon the guidewire30.

The delivery catheter 64 contains the stent dock 280 and is directedinto the left atrium 46. An atrial portion 280 a of the stent dock 280is extruded (i.e., extended) by withdrawing the delivery catheter 64 asthe stent dock 280 is held in place as shown in FIGS. 15B and 15C. Thiscould also be accomplished by pushing the stent dock 280 outward fromthe delivery catheter 64. It is appreciated that, although the stentdock 280 can be constructed in a variety of ways, it is useful toconstruct the stent dock 280 from a shape memory material such asNitinol. It should be noted that the stent dock 280 may be cut from atube or piece of material, or may be woven from threads or pieces ofshape memory material. Preferably, the stent dock 280 has an option ofallowing blood to flow around it and through it. This is facilitated bythe stent matrix as shown in FIG. 15B. In one embodiment of theinvention, portions of the stent dock 280 may be coated with one or moreof fabric, polymers, and biologic material. It is noted that a fabriccoating may be particularly useful to prevent leaks and encourage tissueingrowth around the annulus 84 of the mitral valve 44. Suitable fabricsmay include Dacron and Teflon materials.

After the atrial portion 280 a of the stent dock 280 is released, thestent dock 280 and delivery catheter 64 are lowered together as shown inFIGS. 15C and 15D so that the atrial portion 280 a of the stent dock 280may contact the atrial wall 46 a and the valve anchoring portion 280 bof the stent dock 280 is positioned within the mitral valve 44 as shownin FIG. 15D. The valve anchoring portion 280 b may also be coated withmaterial such as Dacron or Teflon to promote tissue ingrowth and helpprevent leaks. As illustrated in FIG. 15E, the delivery catheter 64 isretracted further and releases anchoring arms in the form of ventricularhooks 284 of the stent dock 280, allowing the hooks 284 to travelbetween the chordae tendineae 48 and wrap around the mitral valveleaflets 38, 42. The atrial portion 280 a retains the stent dock 280 inthe left atrium 46 and the stent dock 280 is held stable inside theheart 14. The valve anchoring portion 280 b is in a closed position, butmay expand in the direction of the arrows upon insertion of a valveprosthesis 120 (FIG. 15G). It should be noted that the native mitralvalve 44 may still open and close so that the heart 14 still functionsand the patient remains stable during the procedure. Therefore, there isno critical time constraint placed on the operator while preparing toimplant the valve prosthesis 120.

It is appreciated that other methods of stent dock deployment may beused within the scope of the present invention. For example, otherembodiments (not shown) may incorporate a delivery catheter device ordevices constructed so that the stent dock 280 can be released from twoends. In one embodiment a catheter could retain the atrial portion 280 awith or without the valve anchoring portion 280 b of the device and aseparate catheter could retain the ventricular hooks 284. The moreproximal catheter could be withdrawn to allow the hooks 284 to openfirst. This step could be performed with the hooks 284 low in theventricle 10 and the entire stent dock 280 could be pushed forwardtoward the valve 44, ensuring that the valve leaflets 38, 42 areretained by the hooks 284. If imaging (for example, echocardiography) isused and shows that part of a valve leaflet 38, 42 is not hooked, thestent dock 280 can be pulled back and re-positioned. When the hooks 284have properly engaged the valve leaflets 38, 42, the more distalcatheter could be withdrawn to allow the atrial portion 280 a to expand.

Additional maneuvers may assist positioning of the stent dock 280. Forexample, restricting leaflet motion may help to allow the hooks 284 tosecure all leaflet components. This could be performed pharmacologicallyby reducing flow through the mitral valve via negative inotropes orvasodilators to pool blood in the periphery of the patient or by tablepositioning. Mechanical devices such as occluders or balloons could beinflated near the mitral valve to limit flow. Alternatively, the atrialportion 280 a of the stent dock 280 could be adapted to impair flow, ora flow impairing stent structure could be incorporated thereon. Inanother embodiment, the atrial portion 280 a could have fabric attachedin part or covering its entire surface to restrict flow. This fabriccould also be used to promote tissue ingrowth and long termbiocompatibility.

Referring now to FIG. 15F, the stent dock 280 has been positioned. Thevalve retaining portion 280 b of the dock 280 has expanded or dilated,causing the hooks 284 to lift or move upward toward the atrial portion280 a of the dock 280. The hooks 284 pull upward on the mitral valvetissue so that the valve 44 may no longer open and close. Also, themitral valve leaflet tissue 38, 42 is compressed by the hooks 284 toform an excellent gasket or seal around the stent dock 280. The mitralleaflet tissue 38, 42 forms a ring of compressed native biologicmaterial that strengthens the dock 280 and prevents any leaks around thestent dock 280. Therefore the expansion of the valve retaining portion280 b causes the atrial portion 280 a and hooks 284 to hold the dock 280in place. The expansion of the valve retaining portion 280 b can beeffected by a variety of means. In one embodiment a draw string (notshown) could be used to pull the hooks 284 toward the atrial portion.Similarly, in another embodiment a series of draw strings (not shown)could be used to pull hooks 284 and segments of the atrial portion 280 atogether.

It should be noted that both the atrial portion 280 a and theventricular hooks 284 of this device 280 could have many variations. Forexample, the atrial portion 280 a may not be composed of complete cells.In one embodiment the atrial portion 280 a may comprise radial arms (notshown) extending outward and not a complete circle of stent material. Inanother embodiment the atrial portion 280 a could comprise a spiral ofmaterial similar to the tail-like extension 162 shown previously toanchor the helical anchor in the atrium in FIG. 8.

Following successful placement of the stent dock 280, a separate valveprosthesis 120 is implanted within the valve retaining portion 280 b asshown in FIG. 15G. The valve prosthesis 120 may be as previouslydescribed, for example. The expansion of the valve prosthesis 120 maycause the retaining portion 280 b to expand, which allows the hooks 284and atrial portion 280 a to firmly retain the stent dock 280.Alternatively, the valve prosthesis 120 may be integrated within thestent dock 280 prior to implantation to avoid the secondary step.

FIGS. 16A-16C show the stent dock deployment without a delivery catheterto provide closer detail. The atrial portion 280 a is shown opening inFIGS. 16A and 16B. The spaces between the struts 290 of the atrialportion allow for minimal or no interruption of blood flow. FIG. 16Cshows the atrial portion 280 a resting in the plane 292 of the mitralvalve, shown in dash-dot lines. The valve retaining portion 280 a isbeginning to expand, causing the hooks 284 to elevate. FIG. 16Dillustrates the valve retaining portion 280 b is fully expanded,resulting in the hooks 284 being lifted to their deployed position.

Referring now to FIGS. 17A-17D, a system and method for positioning ahelical anchor 300 in the mitral position of a patient's heart 14 isshown. A catheter 302 is introduced into a patient's venous system bypercutaneous puncture or by a small surgical cut down at the patient'sgroin, as is commonly known. Alternatively, the catheter 302 may beintroduced anywhere in the lower abdomen or retroperitoneal region, orin the neck or shoulder regions via the subclavian or axillary veins orthe jugular system in the neck. In this embodiment, the catheter 302 isadvanced up the inferior vena cava 212, into the right atrium 210,across the atrial septum 304, and into the left atrium 46 as shown inFIG. 17A. The tricuspid valve 306, right ventricle 210, superior venacava 214, and aorta 18 of the patient's heart 14 are show forillustrative purposes. A coil guide catheter 310 is carried by thecatheter and extends between the anterior and posterior leaflets 38, 42of the mitral valve 44 into the left ventricle.

In this embodiment the system is preferably inserted via the venoussystem, which is low in pressure and can accommodate large catheters andguides. This allows flexibility in developing and introducing catheters,systems, devices and methods for remote mitral valve replacement.However, it is appreciated that the system may be introduced directlyinto the left atrium 46 without a transvenous approach, or via the aorta18. For example, the catheter 302 can be passed from the aorta 18 to theleft ventricle 10 and then into the left atrium 46. The aorta 18 can beaccessed directly as in an open surgical procedure, or from any of itsbranches so that the system may be introduced in the groin, shoulder,retro peritoneum, chest, or abdomen of the patient.

In FIG. 17B a coil guide catheter 310 is extended into the leftventricle 10 and assumes its original shape. In this embodiment, thecoil guide catheter 310 comprises a stem 312 and a U-shaped portion 314.The lower coils 316 (FIG. 17C) of a helical anchor 320 are extruded(i.e., extended) from the coil guide catheter 310 inside the ventricle10. The lower coils 316 wrap around the chordae tendineae 48 and themitral valve 44. The precise level at which the lower coils 316 areextruded can be determined by adjusting the level of the coil guidecatheter 310 in the left ventricle 10. In this embodiment the extrusionis commenced below the level of the valve 44 such that the chordaetendineae 48 and the valve 44 are encircled. It may be more convenientto encircle at a higher level. The chordae tendineae 48 originate fromtwo papillary muscle heads 56, 60 located substantially below the mitralvalve 44. Due to the higher concentration of the chordae tendineae 48near the papillary muscle heads 56, 60, it may be desirable to encirclethe chordae tendineae 48 at a lower level.

When the lower coils 316 of the helical anchor 320 have been deliveredbelow the mitral valve 44 as desired, the coil guide catheter 310 isdrawn up into the left atrium 46. See FIG. 17C. The act of withdrawingthe coil guide catheter 310 into the atrium 46 can be used to pull thelower coils 316 of the helical anchor 320 placed in the ventricle 10 toa higher level in order to contact the mitral valve 44 as shown in FIG.17C. The upper coils 322 of the helical anchor 320 are released in theatrium 46 by retracting the coil guide catheter 310 inside the catheter302. When the helical anchor 320 has been delivered in place as shown inFIG. 17D, the coil guide catheter 310 is retracted and the catheter 302is withdrawn. In this embodiment, coils 316, 322 of the anchor 320contact the mitral valve 44 both above and below the leaflets 38, 42.However, it is appreciated that other embodiments may have a variety ofarrangements including those previously described. For example, theupper coils 322 may not contact the mitral valve 44 but may be supportedagainst the atrial wall 46 a. Also, a helical anchor having a gapbetween the lower and upper coils 316, 322 could be positioned so thatthe leaflets 38, 42 are not trapped between coils 316, 322 and toimprove orientation of a subsequently placed valve prosthesis (notshown). FIG. 17D also illustrates that ventricular coils 316 containleaflets 38, 42. It will be appreciated that there may be gaps betweencoils 316 and/or gaps between coils 322, and that different numbers ofcoils than those shown in the drawings may be utilized. As one furtherexample, if additional coils 316 are used in the ventricle 10, this canprovide further prosthetic valve support and help further contain theanterior leaflet 38 from obstructing the aortic valve 22. Additionalcoils 322 in the atrium 46 can also provide further prosthetic valvestabilization and also allow the prosthetic valve to be positionedhigher in the atrium 46 so that it does not obstruct the aortic valve22.

It should be noted that when the helical anchor 320 is delivered thisway, the lower and upper coils (i.e., ventricular and atrial coils) 316,322 are joined by a segment of the anchor that is located at theleaflets 38, 42. This may impair leaflet closure and cause a leak in thevalve 44. However, this situation will not persist for a long time sincea percutaneous replacement valve 120 can be deployed immediately afterplacing the anchor 320. Also, the segment of the anchor 320 joining theatrial coils 322 and ventricular coils 316 may sit near a commisure 80(FIG. 15A) and not interfere with valve closure. In another embodimentthe wire of the anchor 320 could be preformed so that it would travelthrough the center of the native mitral valve 44 and allow the twomitral valve leaflets 38, 42 to approximate each other. A wide varietyof helical panchor configurations, such as those previously describedherein, may be incorporated.

Referring now to FIGS. 18A-18C, a system and method for positioning ahelical anchor 330 in the mitral position of a patient's heart 14 isshown. A catheter 332 is introduced into a patient's venous system bypercutaneous puncture or by a small surgical cut down at the patient'sgroin, as is commonly known. Alternatively, the catheter 332 may beintroduced anywhere in the lower abdomen or retroperitoneal region, orin the neck or shoulder regions via the subclavian or axillary veins orthe jugular system in the neck. In this embodiment, the catheter 332 isadvanced up the inferior vena 212 cava, into the right atrium 210,across the atrial septum, and into the left atrium 46 as shown in FIG.18A. A coil guide catheter 340 extends from the catheter 332 into theleft atrium 46 with its distal tip 340 a at or near the mitral valve 44.The helical anchor 330 is extruded from the tip 340 a of the coil guidecatheter 340 under the mitral valve 44 through a commisure 80 betweenthe anterior and posterior leaflets 38, 42. The coil guide catheter 340comprises a stem 342 and a U-shaped portion 344 to assist in theextrusion of the helical anchor 330.

In this embodiment the system is preferably inserted via the venoussystem, which is low in pressure and can accommodate large catheters andguides. This allows flexibility in developing and introducing catheters,systems, devices and methods for remote mitral valve replacement.However, it is appreciated that the system may be introduced directlyinto the left atrium 46 without a transvenous approach, or via the aorta18. For example, the catheter 332 can be passed from the aorta 18 to theleft ventricle 10 and then into the left atrium 46. The aorta 18 can beaccessed directly as in an open surgical procedure, or from any of itsbranches so that the system may be introduced in the groin, shoulder,retro peritoneum, chest, or abdomen of the patient.

After the lower coils 346 have been positioned under the mitral valve 44in the ventricle 10 as desired, upper coils 348 may be positioned abovethe mitral valve 44 in the atrium 46. In this embodiment, approximatelytwo lower coils 346 of the anchor 330 are positioned under the mitralvalve 44. It is appreciated that any desired number of coils 346 may bepositioned under the mitral valve 44. The upper coils 348 of the anchor330 are released from the coil guide catheter 340 above the mitral valve44 by rotating the coil guide catheter 340 as shown in FIG. 18B. In thisembodiment, the catheter 332 has a turn 332 a at its distal end. Inother embodiments, the turn 332 a may be deactivated so that the uppercoils 348 are delivered above the valve 44 from a location closer to theatrial septum 304. This would allow the coils 348 to assume theirpreformed position with relative ease, and would eliminate the need torotate the catheter 332. FIG. 18C illustrates the completed placement ofthe helical anchor 330 in the mitral position, such that approximatelytwo lower coils 346 of the anchor 330 are positioned under the mitralvalve 44 and approximately two upper coils 348 are positioned above themitral valve 44. In this embodiment, coils 346, 348 on both sides of thevalve 44 contact the valve leaflets 38, 42. After anchor placement iscomplete, the coil guide catheter 340 is retracted and the catheter 342may be withdrawn.

Referring now to FIGS. 19A-19E, a system and method for positioning astent dock 350 in the mitral position of a patient's heart is shown. Thestent dock 350 may be constructed as described in connection with FIGS.16A-16D, or in any other suitable manner to carry out the inventiveprinciples as described herein. A catheter 352 is introduced into apatient's venous system by percutaneous puncture or by a small surgicalcut down at the patient's groin, as is commonly known. Alternatively,the catheter 352 may be introduced anywhere in the lower abdomen orretroperitoneal region, or in the neck or shoulder regions via thesubclavian or axillary veins or the jugular system in the neck. In thisembodiment, the catheter 352 is advanced up the inferior vena cava 212,into the right atrium 210, across the atrial septum 304, and into theleft atrium 46 toward the mitral valve 44 as shown in FIG. 19A. Adelivery catheter 354 extends from the catheter 352 across the mitralvalve 44 into the left ventricle 10. The stent dock 350 is extruded fromthe delivery catheter 354 within the left ventricle 10 such that hooks356 of the stent dock 350 are released from the delivery catheter 354and are positioned around the mitral valve leaflets 38, 42 as shown inFIG. 19B. To ensure that all parts of both the anterior and posteriorleaflets 38, 42 are engaged by the hooks 356, the stent dock 350 can bepulled toward the valve 44 as shown in FIG. 19C. If this method fails,the stent dock 350 can be pushed forward and the process repeated.Furthermore, the hooks 356 can be retracted back into the deliverycatheter 354 in order to restart or abandon the process if there isdifficulty in engaging both leaflets 38, 42. After the hooks 356 havebeen successfully positioned, the entire stent dock 350 is released fromthe delivery catheter 354 such that a valve retaining portion 350 isplaced between the anterior and posterior leaflets 38, 42 of the mitralvalve 44 and an atrial portion 350 a expands to its original shapewithin the left atrium 46 as shown in FIG. 19D. A valve retainingportion 350 b may have shape memory characteristics that allow it toexpand spontaneously, or the valve retaining portion 350 b may beexpanded by a balloon. The expansion of the valve retaining portion 350b causes the hooks 356 to move upward and secure the valve leaflets 38,42 such that the hooks 356 and atrial portion 350 a of the stent dock350 clamp upon the mitral valve 44, stabilizing the stent dock 350 inplace and forming a seal around the stent dock 350. In this embodiment avalve prosthesis 360 is integrated into the system as shown in FIG. 19E.The valve prosthesis 360 comprises two artificial leaflets 362, 364which are mounted within the valve retaining portion 350 b. Theartificial leaflets 362, 364 may comprise pliable animal tissue such ascow, pig or horse pericardium or animal valve tissue or any othersuitable material, as with all other embodiments. It is appreciated thatother embodiments may require the additional step of implanting aseparate valve prosthesis within the valve retaining portion 350 b ofthe stent dock 350.

In another embodiment, orientation relative to the mitral valve 44 canbe provided. The anterior leaflet 38 is larger than the posteriorleaflet 42 and is situated adjacent to the aortic valve 22 whereas theposterior leaflet 42 is closely associated with the posterior wall ofthe heart 14. It may be useful for example, to provide longer hooks 356on the stent dock 350 where it attaches to the anterior mitral leaflet38. To orient the prosthesis 360, an operator can direct a guidewire orother orienting object (not shown) through the aortic valve 44. Thiswill give the operator an orientation on how to turn the prosthesis 360for optimal alignment. More specifically, the aortic valve 22 is locatedadjacent the anterior leaflet 38. Therefore, passing a guidewire intoand through the aortic valve 22 will allow visualization, for example,on fluoroscopy and show the operator how to orient the stent dock 350and properly orient or place the anchoring arms, e.g., hooks 356 toretain and secure the anterior leaflet 38 such that it does not obstructthe aortic valve 22. Alternatively, the orientation can be performedautomatically by directing a guidewire through the aortic valve 44 suchthat the guidewire is passed through a lumen on the delivery system,e.g., a delivery catheter 352, for the stent dock 350. A guide wire (notshown) may be passed through the delivery catheter 352 and out throughthe aortic valve 22 via the left ventricle 10. This will give theoperator an orientation view of the delivery system by way of afluoroscope, for example. The stent dock 350 can then be directedthrough the delivery catheter 352 such that a channel in the deliverycatheter that holds the guide wire is adjacent to a portion of the stentdock 350 that will abut the anterior leaflet 38, and adjacent to thosehooks or other anchoring arms that will secure the anterior leaflet 38.The location of the guidewire or other orienting structure turns thestent dock 350 so that it orients to the anterior mitral valve leaflet38 in this manner.

Referring now to FIGS. 23A-23D, a system and method for positioning ahelical anchor 370 in the mitral position of a patient's heart 14 withthe assistance of an aortic guidewire 372 and a positioning helix 374 isshown. A guidewire 372 is advanced from a lumen 376 of an introducer 378into the left ventricle 10, across the aortic valve 22, and into theaorta 18. The right ventricle 210 is shown for illustrative purposes.The guidewire 372 may be used to locate the anterior leaflet 38, whichis proximate the aortic valve 22. A coil guide catheter 380 having astem 382 and a U-shaped portion 384 is advanced from the lumen 376 ofthe introducer 378 and is positioned with its distal tip 380 a in theleft atrium 46 as shown in FIG. 23B, so that the distal tip 380 a of thecoil guide catheter 380 may be aimed away from the guidewire 372, asshown, or it may be aimed toward the guidewire 372. An operator may usefluoroscopy or echocardiography to determine the direction of the distaltip 380 a relative to the guidewire 372. If the distal tip 380 a isaimed away from the guidewire 372, then the operator is assured that asubsequent positioning helix 374 will be extruded from the coil guidecatheter 380 toward the posterior leaflet 42. Conversely, if the distaltip 380 a is aimed toward the guidewire 372, then a subsequentpositioning helix 374 will be extruded from the coil guide catheter 380toward the anterior leaflet 38. It will be appreciated that this type ofguide wire assistance may also be used via an atrial approach whereinthe guide wire 372 is delivered via a catheter from the atrium 46 andthen through the mitral valve 44 and turned upward through the aorticvalve 22.

Prior to placing a helical anchor 370 in the mitral position, apositioning helix or spring 374 can be advanced from the coil guidecatheter 380 into the left atrium 46 as shown in FIG. 23B. The leftatrium 46 narrows at the location of the mitral valve 44 such that thevalve 44 resembles a drain. The positioning helix 374 shown is largerthan the diameter of the annulus 84. For example, a positioning helix374 with a maximum diameter of 40 mm may be used for a 30 mm annulus 84.The positioning helix 374 is advanced when the coil guide catheter 380is in the middle of the atrium 46 so that the helix 374 will fullyexpand. When the coil guide catheter 380 is retracted toward the mitralvalve 44, the operator can feel the force of the helix 374 against theatrial wall 46 a adjacent to the annulus 84 and may also see adeflection of the helix 374 away from the plane of the valve 44 whenfluoroscopy or echocardiography is used. This positioning helix orspring 374 serves to identify the location of the mitral valve 44 tomake it easier to locate the annulus 84. The helix 374 can be made fromany appropriate metal and particularly a shape memory material. Thehelix 374 shown has approximately one turn or coil, although any numberof coils could be incorporated.

After the positioning helix 374 has located the mitral valve 44, ahelical anchor 370 is advanced from the coil guide catheter 380 into theatrium 46, through a commisure 80 of the mitral valve 44, and into theventricle 10 below the valve 44 as shown in FIG. 23C. The positioningspring 374 can then be removed from the atrium 46. In this embodiment,approximately two lower coils 390 of the helical anchor 370 are placedbelow the valve 44 by extruding the helical anchor 370 from the coilguide catheter 380. Upper coils 392 of the helical anchor 370 are thenplaced above the valve 44 by rotating the coil guide catheter 380 as thehelical anchor 380 is pushed forward as shown in FIG. 23D. A positioninghelix or spring 374 can be incorporated into any of the systems andmethods for positioning a helical anchor in the mitral position of apatient's heart described herein.

Referring now to FIGS. 24A, 24B, and 24C, another embodiment of a systemand method for positioning a helical anchor 400 in the mitral positionof a patient's heart 14 with the assistance of a positioning helix 402is shown. A catheter 404 is introduced into a patient's venous system bypercutaneous puncture or by a small surgical cut down at the patient'sgroin, as is commonly known. Alternatively, the catheter 404 may beintroduced anywhere in the lower abdomen or retroperitoneal region, orin the neck or shoulder regions via the subclavian or axillary veins orthe jugular system in the neck. In this embodiment, the catheter 404 isadvanced up the inferior vena cava 212, into the right atrium 210,across the atrial septum 304 and into the left atrium 46 as shown inFIG. 24A. A coil guide catheter 406 extends from the catheter 404 intothe left atrium 46 toward the mitral valve 44. The coil guide catheter406 comprises a stem 408 and a U-shaped portion 410 for assisting theextrusion of the positioning helix 402 and a helical anchor 400therefrom. A positioning helix 402 is extruded from the coil guidecatheter 406 and is pushed against the bottom of the left atrium 46 nearthe mitral valve 44. This causes a backforce that can be felt by theoperator to confirm the location of the mitral valve 44. A helicalanchor 400 is then extruded from the coil guide catheter 406 under themitral valve leaflets 38, 42 using the positioning helix 402 as a guideas shown in FIG. 24B. The positioning helix 402 can be removed after aportion of the helical anchor 400 is placed below the leaflets 38, 42.The removal of the catheter 404 following the completed placement of thehelical anchor 400 with coils 404, 406 respectively above and below thevalve is shown in FIG. 24C. It should be noted that in other embodimentsthe positioning helix 402 could have additional features. For example,it may incorporate a tail-like extension which can pass through the leftventricle and into the aorta (not shown) at its distal end. This featurewould ensure that the positioning helix 402 is substantially centeredaround the mitral annulus 84. In addition the positioning helix 402would deviate when pushed against the base of the atrium 46. Such adeviation would show up to the operator on the fluoroscope and show theposition of the helix 402.

As previously described herein, when the end of an anchor deliverysystem is located inside the atrium 46, the helical anchor must bedirected under the valve leaflets 38, 42. Therefore, additional devicesand methods which will now be described are useful to assist thepositioning of the start of the helical anchor under the valve leaflets38, 42 without the need for visualization or with minimal visualizationand maximal assurance of the location of the starting point of theanchor so that coils of the anchor will ultimately be located both aboveand below the leaflets 38, 42.

Referring now to FIGS. 25A-25C, a system and method for positioning ahelical anchor 420 in the mitral position of a patient's heart 14 isshown. A guidewire 422 is advanced from an introducer 424 through theleft ventricle 10 and into the left atrium 46 via the mitral valve 44. Acatheter 426 containing a coil guide catheter 428 having an attacheddrawstring 430 and a central lumen 432 is advanced over the guidewire422 so that the coil guide catheter 428 extends into the left atrium 46as shown in FIG. 25A. In another embodiment, the coil guide catheter 428may have two lumens for each of the guidewire 422 and the helical anchor420. This variation prevents the two wires 420, 422 from interferingwith easy passage of one another if they are in place at the same time.Interference might be particularly problematic in a coil guide catheter428 having a single lumen when inserting a helical anchor 420 comprisinga shape memory material, which could create kinks that would impair themovement of a guidewire 422 through the lumen 432. Both lumens are notrequired to pass to the end of the coil guide catheter 428. Thedrawstring 430 may be tied around the coil guide catheter 428 orincorporated into the structure of the coil guide catheter 428, or itmay pass through a loop (not shown) in the coil guide catheter 428 forfixation.

The coil guide catheter 428 is initially straight and is activated to acomplex curved shape to facilitate delivery of the helical anchor 420 asshown in FIG. 25B. In general, the activated coil guide catheter 428features curves in two directions. Specifically, a stem 436 of the coilguide catheter 428 is curved to bring the distal end thereof into aplane roughly parallel with the mitral valve 44. A second curve 438roughly parallels the path of the mitral annulus 84. The helical anchor420 is shown passing out of the coil guide catheter 428 and under themitral valve leaflets 38, 42. Anchor delivery under the leaflets 38, 42has been facilitated by the drawstring 430. The drawstring 430 is pulledfrom inside the introducer 424 to draw the coil guide catheter 428 underthe leaflets of the mitral valve 44. The coil guide catheter 428 can betemporarily pulled down inside the left ventricle 10, until it sitsunder the leaflets 38, 42. The helical anchor 420 can be pushed out ofthe coil guide catheter 428 and its turns or coils are started under theleaflets 38, 42. It should be noted that the drawstring 430 passesbetween the leaflets 38, 42 to ensure that the coil guide catheter 428will be drawn down between the leaflets 38, 42. The coil guide catheter428 can be drawn downward in an exaggerated manner (i.e., far into theleft ventricle 10) to ensure the helical anchor 420 starts its turnsunder the leaflets 38, 42. After a segment of the anchor 420 isdelivered, the tension on the drawstring 430 can be released so that thecoil guide catheter 428 will return to its position just under theleaflets 38, 42 and the helical anchor 420 will be positioned just underthe leaflets 38, 42 by simply pushing it out from the coil guidecatheter 428. In this embodiment the procedure is performed via the apex6 of the left ventricle 10. If this procedure is performed via a transseptal puncture, the pulling motion will not work. A pushing motion willbe necessary and so a device with some stiffness would be required tomove the end of the coil guide catheter 428 under the leaflets 38, 42.In one embodiment this could be accomplished simply by running thedrawstring 430 through a tube or catheter and pushing on the catheter(not shown). As shown in FIG. 25B, pulling on the end of the drawstring430 releases a knot 440 and allows the drawstring 430 to be removed.There are other options including cutting the knot 440 or passing thedrawstring 430 through a loop that allows it to be pulled free.

FIG. 25C shows the placement of the helical anchor 420 above the valve44 following the removal of the drawstring 430 and completed anchorplacement below the valve 44. Two coils or turns 442 of the helicalanchor 420 sit under the mitral valve 44 and additional turns 444 areplaced above the valve 44 by simultaneously pushing out the helicalanchor 420 and turning the coil guide catheter 428. It is not necessaryto simultaneously push out the helical anchor 420 and turn the coilguide catheter 428 at the same time. The two steps can be performedseparately. In another embodiment, coils of the helical anchor 420 canbe delivered into the atrium 46 before the tip 420 a of the anchor 420is pushed under the leaflets 38, 42 (FIG. 25B). For example, two coilsof the anchor 420 could be extruded from the coil guide catheter 428into the left atrium 46 before the end 420 a of the anchor 420 isdirected under the mitral leaflets 38, 42. The tip 420 a of the anchor420 could then be passed under the valve leaflets 38, 42 and two moreturns advanced by simply pushing on the helical anchor 420. This wouldresult in a helical anchor 420 positioned with two turns above theleaflets 38, 42 and two turns below the leaflets 38, 42. As statedpreviously, a different number of turns may be provided above and/orbelow the valve 44. By delivering the turns of the anchor 420 beforeengaging the mitral leaflets 38, 42, the need to rotate the coil guidecatheter 428 is eliminated. Only a pushing motion is required. Thisarrangement will allow a helical anchor 428 to be implanted with theoperator only needing to push catheters and tools in and out of thepatient. Any need to turn and rotate catheters, particularly remotely,makes the procedure more difficult. Transferring torque along a catheteris difficult and unpredictable and can result in the catheter either notmoving at all or jumping unpredictably with a risk of heart injury. Acatheter procedure performed with only in-and-out motions is much easierand safer.

Referring now to FIGS. 26A-26C, a system and method of directing ahelical anchor 450 under the mitral valve leaflets 38, 42 is shown. Thisseries of figures shows the helical anchor 450 itself being sprung outof its neutral position and pulled under the leaflets 38, 42. A snare452 is comprised of a loop of suture or wire which can be choked downupon within a catheter or tube 454. In one embodiment, materials may beadded to the loop 452 to allow it to be visualized on fluoroscopy (i.e.radiopaque). Alternatively, the snare 452 could be composed of wire orwire inside a cover such as a suture or a polymer coating. The snare 452can be applied as shown by inserting the snare catheter 454 into theleft atrium 46 and then widely opening the loop 452 to create asubstantially large target to pass the helical anchor 450 through. FIG.26A shows the snare 452 being attached to the end of the anchor 450inside the heart 14. However, this may be difficult to do.Alternatively, the snare 452 could be inserted in a patient with thesnare 452 pre-attached to the end of the helical anchor 450 (which couldbe slightly extruded from the end of a coil guide catheter 456 andcinched to the end of the coil guide catheter 456 before it is placedinside the introducer 2). Alternatively, the loop 452 may be coupled tothe end of the coil guide catheter either before entering the patient,or when in the heart. It will be appreciated that pre-snaring the loop452 to the tip of the coil guide catheter 456 or to the tip or end ofthe helical anchor 450, will generally be easier.

The snare catheter 454 and the coil guide catheter 456 pass through thesame introducer 2 in the apex 6 of the left ventricle 10. When twoobjects pass through the same introducer, there is a tendency for bloodto leak as the closure mechanism cannot seal around the space betweenthe two objects. It may be useful to alter the design of the wall of thecoil guide catheter 456 and/or the snare catheter 454 so the twotogether form a perimeter that is easy to close. For example, the snarecatheter 454 might be made flat or elliptical or crescent shaped whereit passes through the introducer 2 to reduce the risk of blood leakingby improving sealing. There could also be a groove in the introducer 2to accommodate the snare catheter 454.

In FIG. 26B the snare 452 has tightened around the end of the helicalanchor 450 which has been extruded beyond the end of the coil guidecatheter 456. The helical anchor 450 has an enlarged tip 460 to preventthe snare 452 from sliding off of the end of the anchor 450. Theoperator pulls on the snare 452 to deliver the tip 460 of the helicalanchor 450 below the mitral valve 44. Since the snare 452 passes betweenthe mitral valve leaflets 38, 42, the helical anchor 450 will also passbetween the mitral valve leaflets 38, 42. To ensure that the anchor 450is truly under the valve leaflets 38, 42, the anchor 450 can be tuggedin an exaggerated fashion into the ventricle 10 before the coil 450 isadvanced out of the coil guide catheter 456. The snare 452 can bereleased by pulling through a loop of suture or cutting the sutureinside or outside the patient.

In another embodiment it may be useful to allow the snare 452 to bedirected and deflectable. Once the anchor 450 is pulled under theleaflets 38, 42, it may be useful to direct the tip 460 of the anchor450 to the perimeter of the valve 44, particularly to avoid entanglementwith the chordae tendineae. 48 This could be accomplished, for example,by passing a preshaped or malleable rod down the snare catheter 454 togive it a preferred shape. A malleable rod allows the operator to changeits curve. The snare system could also have steerable features such asthose previously described in relation to the coil guide catheters. Ahandle on the outside of the patient could be used to adjust the turn onthe snare system.

To be sure the helical anchor 450 passes wide to all of the chordaetendineae 48, it would be useful to allow the snare 452 or suture to bedeflected toward the perimeter of the valve 44 once the helical anchor450 is pulled under the leaflets 38, 42. This could be done with astylet inside the snare tube 454 or the snare 452 could have featuressuch as those previously described with relation to the coil guidecatheters, allowing it to change shape with a slight bend outward. Theanchor 450 can then be pushed out until it is safely under the leaflets38, 42 for perhaps 2 or 3 cm or about a quarter of a turn (i.e. so theanchor 450 will not spring back into the left atrium 46). After a safeamount of the anchor 450 is pushed under the leaflets 38, 42, the snare452 can be released. The anchor delivery is continued by pushing theanchor 450 out until the desired number of turns are under the leaflets38, 42. If a suture is used, it could be cut. The stiffening rod couldalso be passed through a lumen separate from the suture 452 and stillprovide the same benefit.

FIG. 26C shows the tip 460 of the helical anchor 450 positioned underthe valve 44 and released from the snare 452. An easy way to disengagethe anchor tip 460 from the snare is to pull down on the snare 452 untilthe anchor is bent down into the left ventricle 10 and then release thesnare 452, allowing the anchor 450 to spring out of the snare 452. Thesuture could also be cut outside the patient and then pulled through thesnare 452. The suture could also pass through a preformed loop (notshown) in the tip 460 of the anchor 450. Alternatively, the distal endof the coil guide catheter 456 can be advanced under the leaflets 38, 42by rotating it once the tip 460 of the anchor 450 is under the leaflets38, 42. The snare 452 is then released slightly and the helical anchor450 is then withdrawn back inside the coil guide catheter 456, forcingthe snare 452 off the end of the anchor 450. The suture 452 and snaretubing 454 can be withdrawn through the introducer 2 in the apex 6 ofthe left ventricle 10. The anchor insertion can be completed by pushingout the remainder of the anchor 450 under the leaflets 38, 42, aspreviously described herein.

Referring now to FIGS. 27A and 27B, a coil guide catheter 470 aspreviously described is shown with an additional position settingfeature. FIG. 27A shows the coil guide catheter 470 activated to acomplex curved shape to facilitate delivery of a helical anchor 472. Theactivated coil guide catheter 470 features curves in two directions.Specifically, the stem 474 of the coil guide catheter is curved to bringthe distal end 476 of the coil guide catheter 470 into a plane roughlyparallel with the mitral valve 44. A second curve 478 roughly parallelsthe path of the mitral annulus 84. In FIG. 27B the coil guide catheter470 is shown with an additional curve 480 so that its tip 482 isdeflected further downward. This downward deflection allows the tip 482of the coil guide catheter 470 to pass easily under the mitral valveleaflets 38, 42. For example, the coil guide catheter 470 may assume theshape illustrated in FIG. 27B while a helical anchor is delivered underthe mitral valve leaflets 38, 42 for several centimeters, and then maybe returned to the shape shown in FIG. 27A to ensure that the anchor 472sits correctly under the leaflets 38, 42.

Referring now to FIGS. 28A and 28B, a system and method of directing ahelical anchor 490 under the mitral valve leaflets 38, 42 is shown. Thisseries of figures shows the helical anchor 490 being delivered over aguidewire 492. The guidewire 492 is delivered through the end of a coilguide catheter 494 such that the guidewire 492 passes under the mitralvalve leaflets 38, 42 into the left ventricle 10, as shown in FIG. 28A.The helical anchor 490 having a lumen 490 a is then advanced over theguide wire 492 such that the anchor 490 passes under the mitral valveleaflets 38, 42 into the left ventricle 10, as shown in FIG. 28B. Theguidewire 492 may be withdrawn at any time after the anchor 490 hassuccessfully passed into the left ventricle 10. In this embodiment thehelical anchor 490 is constructed of a solid tube or a stent-likestructure.

Referring now to FIGS. 29A-29C, a system and method of directing ahelical anchor 500 under the mitral valve leaflets 38, 42 is shown. Thisseries of figures shows the helical anchor 500 being withdrawn from itsneutral position and pulled under the leaflets 38, 42 by a grasping tool502. A coil guide catheter 504 is shown inside the left atrium 46 with ahelical anchor 500 retained therein. The end 506 (FIG. 29C) of thehelical anchor 500 is held by the jaws 508, 510 of a separate graspingtool 502. Alternatively, the grasping tool 502 can attach to the helicalanchor 500 along the length of the anchor 500. The grasping tool 502functions similarly to the snare previously described herein, and canextend to the inside of the coil guide catheter 504 or it can hold theend 506 of the helical anchor 500 outside the coil guide catheter 504 asshown in FIG. 29A.

In this illustrative example, the grasping tool 502 features a U turn512 to properly position the jaws 508, 510 of the tool 502 for grippingthe end 506 of the helical anchor 500. The need for a U turn 512 couldbe eliminated simply by having a pivoting joint, such as a universaljoint connection between the end of the grasping tool 502 and the end506 of the helical anchor 500. Alternatively, the ball on the end 506 ofthe helical anchor 500 could mate with a groove in the jaws 508, 510 ofthe grasping tool 502 allowing it to engage at any angle. The graspingtool 502 can be used to draw the helical anchor 500 below the mitralvalve leaflets 38, 42 as shown in FIG. 29B. The grasping tool 502 doesnot need to curve, but rather may pass in a straight course into theleft atrium 46. When the helical anchor 500 is positioned under theleaflets 38, 42, the grasping tool 502 is released and may be withdrawnfrom the heart 14 as shown in FIG. 29C. The anchor 500 may then beadvanced into position under the mitral leaflets 38, 42 as previouslydescribed herein. The grasping tool 502 may function similarly to biopsyforceps.

FIGS. 30A and 30B illustrate an alternative grasping tool 520 inaccordance with the present invention. The grasping tool 520 comprises apair of a jaws 522, 524 and a catheter 526 which allows the jaws 522,524 to open and close. The catheter 526 is advance toward the jaws 522,524 in order to close them and hold the end 506 of the helical anchor500, shown in FIG. 30A. When the catheter 526 is retracted, the jaws522, 524 open and the helical anchor 500 is released, as shown in FIG.30B. This grasping tool 520 is much more flexible and thinner thanbiopsy forceps. Also, the anchor 500 is able to rotate inside the jaws522, 524 of the grasping tool 520. This junction acts as a universaljoint with a ball-shaped end 506 of the helical anchor 500 allowed toswivel inside the grasping tool 520. This allows the coil guide catheter504 and grasping tool 520 to be inserted in a parallel path without theneed for the U turn 512 of FIG. 29A. As previously described herein, itis not necessary for the grasping tool 520 to hold the end 506 of thehelical anchor 500. Rather, the grasping tool 520 may latch onto thehelical anchor 500 at any point along its length. With the grasping tool520 latched on to the side of the helical anchor 500 it is possible toallow the anchor 500 to slide through the jaws 522, 524 so the anchor500 can be pushed into place while the jaws 522, 524 are closed and thegrasping tool 520 is held in place.

Referring now to FIGS. 31A-31D, a system and method of positioning thehelical anchor 500 in the mitral position of a heart 14 is shown. A coilguide catheter 504 and a separate grasping tool 520 are advanced intothe left atrium 46 through an introducer 2. The end 506 (FIG. 31C) ofthe helical anchor 500 comprises a ball shaped tip which extends fromthe coil guide catheter 504 and is held by the jaws 522, 524 of thegrasping tool 520. A portion of the helical anchor 500 is positioned inthe atrium 46 by pushing the anchor 500 through the coil guide catheter504, as shown in FIG. 31A. After approximately two coils 530, 532 havebeen positioned in the atrium 46, the grasping tool 520 is retractedthrough a commisure 80 to draw the end 506 under the mitral annulus 84as shown in FIG. 31B. When the end 506 of the helical anchor 500 hasbeen drawn under the annulus 84, the grasping tool 520 releases the end506 of the anchor 500 and is withdrawn from the heart 14 as shown inFIG. 31C. The helical anchor 500 is then further extruded from the coilguide catheter 504 such that approximately two coils 534, 536 of theanchor 500 are positioned below the annulus as shown in FIG. 31D. Itshould be noted that this embodiment does not require any twisting orturning of the coil guide catheter 504, but rather the delivery of thehelical anchor 500 is accomplished only by extrusion.

It should be noted that when the grasping tool 520 is clamped to the tip506 of a helical anchor 500, the grasping tool 520 may wrap around thestem of the coil guide catheter 504 as the turns of the anchor 500 areextruded. This wrapping could be counteracted by simply pre-wrapping thegrasping tool 520 around the stem of the coil guide catheter 504 in anopposite direction before it is inserted inside the heart.Alternatively, the grasping tool 520 may be clamped to the tip 506 ofthe helical anchor 500 after the turns or coils 530, 532 of the anchor500 have been extruded into the atrium 46. However, this may be verydifficult to perform with minimal or no visualization. It is alsopossible to add magnetic materials to the ends of the grasping tool 520and helical anchor 500 so that they can be joined by bringing theirdistal ends in proximity. One or both of the distal end(s) of thegrasping tool and the anchor 500 could be magnetic. If only one ismagnetic, then the other end must contain a material that can be inducedto have a magnetic field such as iron. Even with the aid of magnets, theprocess may still be very difficult to perform with minimal orvisualization. Therefore, other means may be provided to prevent theentanglement of the grasping tool and the coil guide catheter. It shouldalso be understood that while grasping tools and snare catheters arespecifically disclosed herein as suitable control elements used forpurposes of guiding other components of the system, such as the coilguide catheters and/or the helical anchors, other control elements maybe used instead. As one other possible option, a simple cable, suture orother tensile member may be used for pulling on the distal end of acatheter, such as the coil guide catheters of this invention, orotherwise pulling directly or indirectly on the helical anchor itselffor positioning purposes.

Referring now to FIGS. 32A-32E, a system and method of directing ahelical anchor 500 under the mitral valve leaflets 38, 42 is shown. Acoil guide catheter 504 is advanced into the left atrium 46 by means ofan introducer 2 such that the stem of the coil guide catheter 504 isplaced in a commisure 80 of the mitral valve 44. The terminal end 504 aof the coil guide catheter 504 is shaped so that it is located near theother commisure 80. The length of the coil guide catheter 504 is chosenso that when the helical anchor 500 is extruded as shown in FIG. 32A,the end 506 of the anchor 500 may be grabbed by a grasping tool 504 thatpasses quite precisely through the commisure 80. A plurality of coilguide catheters can be manufactured in a variety of dimensions to matchdifferent sizes of mitral valves. For example, an operator could selecta coil guide catheter 504 having a length of about 30 mm between the endof the stem and the tip 504 a of the guide 504 when performing theprocedure on a patient with a mitral valve diameter of about 30 mm(shown generally on echocardiography and also on CT and MR scanning).

FIG. 32B shows a view of the mitral valve 44 from above. The coil guidecatheter 504 is passing through the mitral valve 44 at the commisure 80shown on the right. The stem 504 b of the coil guide catheter 504 can beguided by echocardiography to reach one of the commisures 80. The end ofthe coil guide catheter 504 has a U-shaped portion 504 c which issimilar to the arc of the posterior mitral annulus and the distal tip504 a sits near the other commisure 80 so that a helical anchor 500 maybe extruded therefrom and pulled under the leaflets 38, 42 by thegrasping tool 540. It should be noted that it is not necessary toposition the entry point of the anchor 500 at a commisure 80. However,it is important to recognize that if, for example, the helical anchor500 is started in the middle region of the anterior mitral valve leaflet38, this part of the leaflet 38 may become trapped in the coils andcause problems such as causing the valve 44 to leak after the anchor 500is inserted. If the valve 44 leaks, then the patient may becomehemodynamically unstable and the procedure to insert a mitral valveprosthesis may become rushed.

As shown in FIG. 32B, the U-shaped portion 504 c of the coil guidecatheter 504 tracks the annulus 84 of the valve 44. The U-shaped portion504 c could also track beyond the annulus 84, so that the coil guidecatheter 504 sits against the left atrial wall 46 a over the base of theheart 14. This provides a type of shelf for the coil guide catheter 504to abut on. The operator can pull down on the stem 504 b of the coilguide catheter 504 and feel the coil guide catheter 504 engage againstthe base of the heart 14. This will allow a relatively blind positioningof the depth of the coil guide catheter 504 inside the heart 14.

The grasping tool 540 is advanced into the left atrium 46 through theintroducer 2 so that the grasping tool 540 passes through the mitralannulus 84 close to a commisure 80 as shown in FIG. 32C. The graspingtool 540 comprises jaws 542, 544 which are initially open for receivingthe helical anchor 500. The grasping tool 540 can then clamp the helicalanchor 500 proximate its tip 506 so that the anchor 500 may slidethrough the jaws 542, 544 of the grasping tool 540, as shown in FIG.32D. In one embodiment, the grasping tool 540 may have a lock on thejaws 542, 544 so that the operator does not have to hold the tool 540closed. Such locks are well known and have been described on many toolssuch as endoscopic biopsy forceps. It should be noted that a operatormay prefer to clamp the grasping tool 540 upon the helical anchor 500outside the patient prior to inserting the coil guide catheter 504 andgrasping tool 540 inside the heart 14. FIG. 32E shows the helical anchor500 sliding between the jaws 542, 544 such that the grasping tool 540guides the advancement of the anchor 500 under the valve leaflets 38,42. The jaws 542, 544 are located above the valve 44, but it isappreciated that the jaws 542, 544 may alternatively be below the valve44 or at the same level as the valve 44 to aim the path of the anchor500. The grasping tool 540 is useful not only to pull the anchor 500under the annulus 84, but to control the motion of the anchor 500 andguide the anchor 500 into position. If the anchor 500 becomes stuckwhile turning, the anchor 500 can be advanced and withdrawn with upwardand downward motions on the grasping tool 540 to help free the anchor500. In another embodiment, the grasping tool 540 can also be attachedto the tip 506 of the helical anchor 500 so that it can turn with theanchor 500. If the tip 506 of the helical anchor 500 cannot moveforward, the grasping tool 540 can be rotated with the anchor 500 and bypushing and pulling on the grasping tool 540, the tip 506 of the anchor500 can be coaxed to make the complete turnaround the underside of thevalve 44.

The distance of the coil guide catheter 504 along the U-shaped portion504 c from the stem 504 b to the tip 506 of the coil guide catheter 504can approximate the mitral annulus diameter or the distance between thecommisures 80. When the distance from the end of the stem 504 b to theend 506 of the coil guide catheter 504 are approximately the mitralvalve diameter or the intercommisural distance, the grasping tool 540and the stem 504 b can be separated by the mitral valve diameter or theintercommisural distance such that the system is centered inside themitral valve 44. The commisures 80 are easy to identify onechocardiography. By ensuring that the stem 504 b and the grasping tool540 are sitting in the commisures 80, the delivery of the coil 500 canbe correctly oriented relative to the valve leaflets 38, 42. Mostoperators will likely wish to deliver the coil 500 starting at thecommisures 80, so orienting the coil guide catheter 504 and the graspingtool 540 as shown will guarantee the correct starting position for theentry point of the helical anchor 500.

It should be restated that it is not necessary to deliver the helicalanchor 500 at the commisures 80. The coil guide catheter 504 can berotated so that any entry point is used. However, the commisures 80 maybe useful starting points so that the positions of the stem 504 b of thecoil guide catheter 504 and the grasping tool 540 can be confirmed. Thecoil guide catheter 504 and grasping tool 540 can then be rotated to anydesired entry point for the helical anchor 500.

Sometimes there is calcium under a mitral valve leaflet 38 and/or 42.The helical anchor 500 may not slide easily as it hits a deposit ofcalcium. The grasping tool 540 could be pulled downward and move theanchor 500 to a slightly lower position to navigate around the calcium.Similarly, the helical anchor 500 may go off course and rather than turninto position just below the valve 44 and in the plane of the valve 44,it may take a skewed course. The grasping tool 540 can be used toprevent or remedy this problem. By sliding the helical anchor 500between the jaws 542 544, it is possible to keep the anchor 500 turningon a desirable course. The easy removal of the grasping tool 540 shouldbe noted. The jaws 542, 544 can be opened and the tool 540 simply pulledout of the introducer sheath 2.

Referring now to FIGS. 33 and 33A, a feature for positioning a coilguide catheter 560 within the left atrium 46 is illustrated. A coilguide catheter 560 having a membrane extension 564 is advanced into theleft atrium 44 through a commisure 80 of the mitral valve 44. Theextension 564 lies in the same plane as a U-shaped portion 570 of thecoil guide catheter 560 and travels beyond the perimeter of the mitralannulus 84 so that it sits on the wall 46 a of the left atrium 46.Alternatively, the extension 564 may have a downward turn forming anarched passage around the U-shaped portion 570 of the coil guidecatheter 560. This downward turn would create a space for coils to sitabove the annulus 84 should the operator wish to extrude coils of thehelical anchor 572 before the tip 574 of the anchor 572 is placed underthe mitral valve 44. Referring to FIG. 33, the extension 564 seatsagainst the atrial wall 46 a and provides tactile feedback to theoperator by producing a clear stopping point when the operator pullsback on the coil guide catheter 560. This serves to keep the coil guidecatheter 560 inside the left atrium 46 and in a plane parallel to theplane of the valve 44. In this manner the extension 564 providesassistance with correct depth positioning of the coil guide catheter 560and helps to keep the helical anchor 572 delivery roughly parallel withthe plane of the valve 44. In this embodiment the extension 564 runs thelength of the U-shaped portion 570 of the coil guide catheter 560.However, in other embodiments the extension 564 may be shorter orlonger, even such that the extension 564 may produce a full circlearound the mitral annulus 84. Also, rather than comprising a continuousprojection as shown, the extension 564 could comprise a number ofsmaller separate projections or extensions that perform similarfunctions.

The extension 564 may comprise a membrane of plastic material orbiologic material. Any suitable biologically compatible material couldbe used such as nylon, polypropylene, polyester, PTFE, or ePTFE.Biologic materials such as animal or human pericardium or animalintestinal derived membranes could also be used. A wire-like structure576 may give shape and integrity to the membrane 564. The wire could bemoveable to activate the sail-like membrane 564. For example, pushing onthe wire could move the sail-like membrane 564 from a collapsed positionwhere the membrane 564 sits close to the coil guide catheter 560 to anactive position where the membrane 564 is expanded and provides supportfor the coil guide catheter 560 on the atrial wall 46 a. The wirematerial could be made from any suitable material such as stainlesssteel or Nitinol.

Referring now to FIGS. 34A-34G, a device, system, and method of closingthe commisures 80 of a mitral valve 44 are illustrated. In FIG. 34A asnare catheter 580 is attached to the end of a helical anchor 500 whichextends from the end of a coil guide catheter 504 within the left atrium46 as has been previously described. A suture 582 is tied with a knot584 to connect the snare catheter 580 to the end of the helical anchor500. In other embodiments it may not be necessary to use a knot for thisconnection. For example, the suture 582 could pass through a loop in thetip of the anchor. Or the snare can be tightened around the end of theanchor. However, in this embodiment the knot 584 is useful when thesnare catheter 580 is loosened to maintain attachment to and control ofthe helical anchor 500 to prevent disconnection. The suture 582 can becut at the end of the procedure or any time during the procedure. Therehave been a number of devices described that can be used to cut a suturethrough a catheter. The snare catheter 580 passes between the leaflets38, 42 of the mitral valve 44 near a commisure 80 and the coil guidecatheter 504 passes between the leaflets 38, 42 of the mitral valve 44near the opposing commisure 80 as shown in FIG. 34B. The mitral valveannulus 84 shown here is large, such that about 4 mm to 5 mm of gapbetween the leaflets 38, 42 is shown at each commisure 80. This couldcause a serious leak after a helical anchor 500 and valve prosthesis 120are installed. To prevent this leak, an operator may proceed to implanta mitral valve prosthesis 120 as described herein, and subsequently addprogressively larger amounts of fabric cuff (FIG. 22) to plug the gapbetween the valve prosthesis 120 and the mitral valve annulus 84.However, with a catheter-based implant it is difficult to add asufficient amount of fabric cuff as the material is bulky. Onealternative is to provide a valve prosthesis that is large enough toaccommodate the large mitral valve annulus 84. However, a large valveprosthesis will also be difficult to implant via a catheter. Both largesized valve prostheses and prostheses with cuff material would requirelarge delivery systems requiring large incisions and surgical cut downfor entry into the heart or vascular system.

Alternatively, the mitral valve leaflets 38, 42 could be closed togetheror the space between the leaflets 38, 42 could be corked or plugged. Avariety of devices are available to plug leaks at commisures 80. Deviceslike Amplatzer are composed of coils of metal such a Nitinol orstainless steel. They can have fabric covers or fabric in the interiorto increase thrombogenicity and reduce leak. These plugging devices areused to close atrialseptal defects, patent foramina ovale, paravalveleaks etc. These could be used in this situation. Other devices andmethods could be used to close the commisures 80. A pledget of fabriccould be used to close the gap. A fabric structure with an hourglassshape is one variation that could be inserted so that the narrow part ofthe fabric is positioned in the commisure 80 and the larger part of thefabric is located above and below the valve leaflets 38, 42 would servethis purpose. The plugging material could wrap around the helical anchor500. It does not have to sit on just the outside of the anchor 500. Theanchor 500 could retain the plugging material so there is no risk of thematerial being dislodged. It is also possible to produce occluderdevices, systems and methods that could be integrated or ride on thecoil of the anchor 500. A pledget or amplatzer or other occluder devicecould be anchored to the coil and produce closure at the commisures. Forexample, two occluders could be pre-attached to the coil before itsinsertion. One occluder could be delivered to the first commisure 80.The coil 500 could be advance to the opposite commisure 80 and thesecond occluder could be delivered at this location. The occluders couldtravel along the coil 500 like a guiding rail and could be pushed aroundthe helical anchor, for example, by using a catheter which is fed overthe anchor 500. It is also possible to insert the helical anchor 500 andthen deliver the plugging material along the track or rail of thehelical anchor 500 later. Imaging systems could be used to confirm thatthere was no leak (for example, with echocardiography). Additionaloccluders could be added until no leak occurred. In another embodiment,an occluder that is free-standing could be used to close the commisures80 and prevent leakage. It should be noted that the occluder could bedelivered during or after the positioning of the helical anchor 500.

Another option to prevent a leak around the anchor is to approximate theanterior leaflet 38 and the posterior leaflet 42 together around thehelical anchor 500. FIG. 34C shows a leaflet anchor 590 being placedthrough a mitral valve leaflet 42. When the helical anchor 500 is in thecorrect position, the snare catheter 580 is loosened and maneuvered tothe outside of the helical anchor 500 to one of the leaflets 38, 42.Imaging with fluoroscopy and echocardiography or other techniques mayassist this step. A stiffening rod or a catheter control steering systemcould be useful in manipulating the catheter. The snare catheter 580, ora catheter or lumen associated with it, also delivers leaflet anchors590. The snare catheter 580 may be, for example, a simple double lumencatheter or a separate catheter for delivering the leaflet anchors 590may be joined to the snare catheter 580 near their tips.

In one embodiment, the leaflet anchor 590 is T-shaped and is insertedlike a fabric label anchor commonly used on clothing such that the longstem of the T and the short stem are parallel during insertion. The Tanchor 590 has one sharpened end which is used to penetrate the tissue.The sharp end is fed through a catheter 592 and pushed through theleaflet 42. In another embodiment, the leaflet anchor 590 may bedelivered through a cylindrical tube with a sharpened end to penetratethrough the leaflet tissue. A needle-like distal tipped catheter can beused to deliver the anchor 590 through the leaflet tissue. In any event,the catheter 592 is withdrawn after the T-shaped anchor is pushed out.This leaves the T-shaped anchor on the atrial side of the leaflet 42 andthe tail 594 of the anchor travels through the valve tissue into thecatheter 592.

Once the leaflet anchor 590 has passed through the tissue, it returns toits initial T-shape. The leaflet anchor 590 is then pulled flush withthe valve tissue. The same process is repeated for the other leaflet 38with another anchor 590 as shown in FIG. 34D. Individual anchors 590 arethen cinched tight by fastening their suture ends or tails 594 togetheras shown in FIG. 34G. A tissue suture locker 596 can be used tostrengthen the connection. The locker 596 can be composed of one or moreof a plastic and metal material. At the completion of the plication, thesuture tails 594 are cut.

FIG. 34E shows a second snare catheter 600 advanced upon the coil guidecatheter 504 using a suture connection 602 toward the second commisure80 of the mitral valve. The T anchor plication process is repeated forthe anterior and posterior leaflets 38, 42. FIG. 34F shows the completedplications at both commisures 80.

Alternatively, the helical anchor 500 can be used to enable theplication at the second commisure 80. The helical anchor 500 can beadvanced to the second commisure 80 by pushing it forward. The correctposition for the end of the helical anchor 500 and the anchor deliverysystem can be indicated by the location of the stem 504 b and the use ofimaging methods that can include fluoroscopy, echo, MR and CT. Thehelical anchor 500 both carries and positions the delivery of any anchoror system to plicate leaflets 38, 42 or annulus 84. Once the correctposition has been reached on the commisure 80 shown on the left,fasteners or anchors 590 are again placed through the anterior leaflet38, the posterior leaflet 42 or the annulus 84 as desired. The anchors590 can then be locked together and the suture tails 594 cut to completethe procedure. It should be re-stated that the commisure plication doesnot have to be performed with these specific anchors 590. Any of themany described systems can be used in conjunction with the orienting anddelivery methods and devices described in this disclosure.

In another embodiment, a single anchor could be created that delivers ananchor to each of the anterior and posterior leaflets 38, 42. The twoanchors could be held together by a suture or an elastic material andspring shut after delivery so that the leaflets 38, 42 are approximatedbetween the helical anchor and the annulus. This idea of joining anchorsdoes not apply only to T-shaped anchors, but any anchor.

The helical anchor 500 and/or coil guide catheter 504 is used as a guidefor the delivery of the leaflet and/or annulus anchor 590. Snarecatheters 580, 600 can be used to deliver the anchors 590. The snarecatheters can ride with the helical anchor 500 as it slides around themargin of the annulus 84. The operator can loosen the snare and thenusing imaging (such as fluoroscopy, echocardiographic, MR or CT), movethe snare catheter 580, 600 relative to the helical anchor 500. Thiswill bring the snare catheter 580, 600 toward a correct location such asthe commisure 80. The amount of loosening of the snare 580, 600 can beadjusted to the required location to place an anchor 590. For example,if the gap between the helical anchor 500 and the commisure is 5 mm, theoperator may decide to deliver an anchor 590 about half way between thehelical anchor 500 and the commisure 80—about 2.5 mm from the outside ofthe helical anchor 500. This measure is visible by imaging systems. Ananchor 590 could be delivered into one leaflet 38 or 42, then the otherleaflet 38 or 42. The leaflets 38, 42 can then be approximated.

It may also be useful to plicate the leaflets 38, 42 together at morethan one point if the gap at the commisures 80 is large or if implantinga first anchor pair 590 is not successful in closing the gap between theleaflets 38, 42. If leaflet closure is not successful on its own,plicating the annulus 84 toward the leaflets 38, 42 may be very usefulto prevent leak. This could be simply accomplished by placing an anchor590 into the annulus 84 near or at the commisure 80 and joining it withthe anchors 590 to the leaflets 38, 42.

There are many ways devised to approximate leaflets 38, 42. Clips havebeen pioneered by Abbott's eValve. Anchors do not necessarily need topenetrate leaflet tissue. Non-penetrating anchors could also be used inthe procedure described previously. A variety of anchors have beendescribed by Edwards for their edge-to-edge leaflet repair which waspioneered by the Italian surgeon Ottavio Alfieri. Mitralign haspublished the use of anchors in the annulus. Any of these anchors or anysuitable anchor could be used to accomplish the task of closing thecommisures and preventing paravalvular leak.

These options are described to indicate that many systems devices andmethods can be used to approximate leaflet and annulus tissue. Any ofthese devices and methods could be integrated with this delivery system.The anchors 590 can be carried on the helical anchor 500 or carried withthe snare delivery catheter 580, 600.

It is also possible to plicate the annulus 84 to leaflets 38, 42.Anchors 590 could be placed in the annulus 84 and the leaflets 38, 42 toproduce a “triangular” closure to the commisure 80 and prevent a leak.

Leaks can occur at locations other than commisures 80. For examples,there are often clefts, or gaps between the leaflets 38, 42. Theseclefts can cause leaks. The helical anchor 500 can be used to guideanchors 590 into any location that would benefit from approximationaround the helical anchor 500.

It is also possible, that part of the leaflets 38, 42 is/are notcompletely positioned inside the helical anchor 500. The methods,systems and devices shown here can be used to prevent and eliminateleaks. A gap could be plicated for example by folding a segment of aleaflet 38, 42 together. A pledget of fabric material (Polyester,Dacron, PTFE) or an occluder device (as described previously) could beused.

Combinations of leaflet, annulus and plugging may also be useful. All ofthese could be integrated with the helical anchor 500 and the snarecatheter 580, 600. The use of concentric coils at one plane under theleaflets 38, 42 or above the leaflets 38, 42 with the coils sitting in asingle plan parallel to the mitral valve 44 may also assist in closingthe mitral leaflets 38, 42 and preventing paravalve leaks.

FIG. 34E shows a plication being performed using a catheter 592introduced from the ventricular side of the valve 44. It is clearlypossible to plicate the leaflets 38, 42, commisures 80 or annulus 84from an atrial approach also.

The anchor delivery is also shown using a relatively straight catheter592. Catheter 592 could have other shapes such as a J. A J shape wouldallow delivery of an anchor 590 from the opposite side of the leaflet 38or 42 from catheter entry. For example, a catheter with a J tip could bedelivered from the apex of the left ventricle and directed into the leftatrium 46. An anchor 590 could then be delivered into the leaflet 38 or42 from the atrium 46 towards the ventricle 10.

A snare catheter does not have to deliver the anchor 590. A separateanchor delivery catheter could be used. This could be attached to thehelical anchor 500 or to a snare catheter. A double-lumen catheter maysuit this purpose. One lumen of the snare delivery catheter couldprovide attachment to the helical anchor. The other could serve todeliver the leaflet plication. There could be a gap between the ends ofthe two lumens of a double lumen catheter or a two catheter system. Forexample, a gap of 2.5 mm between the lumens could be useful in providinga plication that is 2.5 mm from the edge of the helical anchor. A numberof fixed gaps could be available depending on the situation. Forexample, if the gap at the commisure might be 7 mm, a catheter with agap of 3.5 mm could be produced. Alternatively, there could be anadjustable gap between the ends of the two lumens to allow for variousanatomical situations. The gap could be adjusted by pulling on the tipof one of the ends of the catheter or a completely steerable tip couldbe produced. A steering system could allow the two lumens to remain at afixed distance, but the entire catheter could be steered by theoperator.

The stem 504 b of the coil guide catheter 504 may be a useful marker forthe location of the commisure 80. One anchor 612 could be deliveredoutside of the stem 504 b of the coil guide catheter 504 between thehelix and the commisure 80. The other anchor 612 can be delivered at thedistal end of the coil guide catheter 504 between its end and thecommisure 80.

Referring now to FIGS. 34H and 34I, a device and method of retaining avalve prosthesis 630 in the mitral position of a heart 14 are shown. Avalve prosthesis 630 is shown prior to placement within a helical anchor632 which has been placed in the mitral position in FIG. 34H. The valveprosthesis 630 features threads or grooves 634 which correspond to theturns or coils 636 of the helical anchor 632. The valve prosthesis mayotherwise be formed as desired, such as described herein. FIG. 34I showsthe valve prosthesis 630 retained by the helical anchor 632 with thegrooves 634 engaging the helical anchor 632. The fit of the coils 636 ofthe anchor 632 and the valve prosthesis 630 is quite precise above themitral leaflets 38, 42, but where the leaflets 38, 42 are securedbetween the coils 636 and the prosthesis 630, the fit is not so precise.Thus, the grooves 634 located below the leaflets 38, 42 may be larger toallow for the tissue of the leaflet to fit in addition to the coils 636.The grooves 634 in the prosthesis 630 could precisely mirror the coils636. This would optimally require the valve prosthesis 630, which isdelivered on a catheter, to land precisely or slide precisely relativeto the coils 636—upward or downward to lock. To increase the chance thata successful non-slipping mating occurs, the grooves 634 could be madelarger in the prosthetic valve 630 to allow for imprecision in thedelivery of the valve prosthesis 630 relative to the helical anchor 632.The grooves 634 could form a continuous thread or the grooves 634 couldbe intermittent. For example, one-third of the helical anchor 632 beingengaged with the prosthesis 630 may be sufficient to preventdislodgement. A pattern of grooves 634 coursing along segments atdifferent levels along the prosthetic mitral valve 630 could accomplishthe same effect. The coils 636 could engage more randomly and stilleffect a solid connection.

The grooves 634 in the prosthetic mitral valve 630 could be much widerthan the coils 636 of the helical anchor 632. For example, two turns ofthe helical anchor 632 could sit in a single groove 634 in the valveprosthesis 630. This would allow more random interaction between theprosthetic valve 630 and the helical anchor 632 to produce a secureconnection. For fabrication, the valve prosthesis 630 could have agrooved shape designed into it, or additional stents or other materialscould be added to the prosthetic valve structure to produce grooves. Forexample, a stent or collapsible tube could be spiraled around the marginof a prosthetic mitral valve that when enlarged, produces a groove toengage the coils 636 of the helical anchor 632. The stent of theprosthetic valve 630 could be folded on itself (imbricated) to producegrooves. This could be accomplished by collapsing segments of the stenton one another. The grooves 634 or imbrecations could be arranged in anypattern including a continuous groove or intermittent grooves. Fabriccoatings on the exterior surface of the prosthetic valve stent could beused to create a mating structure to engage the helical anchor. Forexample, a groove could be created on the outside of the prostheticvalve with a fabric covering wrapped around to create a groove. A bumpysurface could be created by applying segments of fabric to engage thehelical anchor at many locations. For example, rectangles of fabriccould be added to the outer surface of the prosthetic valve stent toengage the coils.

In another embodiment, the prosthetic valve stent could have bumps thatcould collapse where it engages the coil. These features would adapt tothe coil to help engage the prosthetic valve against the coil 632.Alternatively, segments of the prosthetic mitral valve stent could moveoutward. A valve made of Nitinol may have segments that slowly moveoutward to produce a gritty or bumpy surface that adapts to the helicalanchor location. Alternatively, a Nitinol stent may slowly expand suchthat the expansion results in a grooved pattern around the stent thatretains the prosthetic valve more securely inside the coils. A Nitinolstent can be designed to allow its margin to adapt to the grooves of thecoils.

The helical anchor 632 could extend above or below the prosthetic valve630 to engage the ends of the prosthetic valve 630. The helical anchor632 could also be modified. Instead of being completely circular, theanchor 632 could have a generally circular design with segments thatextend inward to engage the prosthetic valve stent 630. The inwardturning segments could also have an upward or downward bias.Alternatively, the helical anchor 632 could be made of a chain of ballsand chains, with the balls able to interact in the spaces of the stentof the prosthetic valve. Enlargements other than circles could be usedalso.

The surface of the helical anchor 632 or the prosthetic valve 630, andany of the implanted components of this invention, such as helicalanchors, docks, or prosthesis may include outer coverings or coatingsfor various purposes, such as friction promoting purposes and tissue ingrowth purposes. For example, the outer surfaces can be roughened tomake slipping or unintended movement of the implanted component lesslikely. The implanted component can be roughened by, for example, sandblasting its surface or chemically etching its surface. Coatings orcoverings such as sleeves of biologically compatible materials could beadded. These could include silicone, polyester, urethanes or any otherdesirable materials. The helical anchors of this invention could haveother friction promoting and/or tissue in growth surfaces composed offabric or even Nitinol or stainless steel to help engage with theprosthetic valve.

The prosthetic valve stent 630 can also be flared at one or both ends.This can be used to prevent dislodgement up or down. Many prostheticvalves are balloon inflated so the balloon that inflates the stent canhave an hourglass shape or just one end flared to expand the valve.

The leaflet commisures of mitral valve leaflets close when they arepressurized. It is unusual to have a serious commissural leak aftervalve repair, because the pressure on the leaflets brings their edgestogether. Any of these helical anchor designs could be modified toencourage closure of the valve commisures by placing the leaflets in thesame position they are when the ventricle is pressurized. The coilsbelow the leaflets in most of the previous figures are “stacked” uponone another—that is each coil is at a different plane as the coilstravel away from the mitral valve when taking the plane of the mitralvalve into consideration.

It is also possible for the coils under the leaflets 38, 42 to beconcentric and at the same time the coils could sit in relatively thesame plane under the leaflet. The diameter of each turn can be slightlywider or narrower with the coils all sitting in approximately the sameplane. This means the coils will sit right under the leaflets 38, 42 ofthe mitral valve 44. By creating a spring force against the annulus 84or leaflets 38, 42, the leaflets 38, 42 will be pushed upward towardtheir closed position as they are when the ventricle 10 is pressurizedin systole. The spring force can come from coils on the opposite side ofthe leaflets 38, 42 that sit against the atrial wall 46 a. The coils canalso be biased upward (to sit against the underside of the native mitralvalve leaflets) in manufacturing to further encourage leaflet appositionat the commisure 80. Closure of the commisures 80 may be bestaccomplished with a series of concentric coils above the leaflets 38, 42and below the leaflets 38, 42 that are arrange to create a compressionforce against the mitral valve leaflets 38, 42 and close the commisures80. In this arrangement the smaller diameter turns of coils under theleaflets 38, 42 can retain the prosthetic mitral valve. The larger turnsor coils can close off the commisures.

For fabrication, a helical anchor that consists of three concentricturns all sitting in one plane may work well. When the helical anchor isinserted with two turns below the leaflets and one turn sitting againstthe atrial wall 46 a, the spring force will tend to pull the turns ofthe helical anchor below and above the commisures 80 together and closethe commisure 80.

Furthermore, it is simple to add additional coils to the helical anchorand simple for the operator to push the coils in position. Combinationsof coils that close the commisures 80 by exerting an upward spring forcewith coils that retain the prosthetic mitral valve 44 may provide anoptimal structure. The coils under the helical anchor can consist of aseries of coils that push the leaflets 38, 42 upward into a closedposition (coils relatively parallel to the plant of the native valve)and coils that retain leaflets 38, 42 (more perpendicular to the nativevalve plane). The coils above the leaflets 38, 42 can abut the leaflets38, 42 on their atrial side or the atrial wall itself.

The use of coils which close the commisure 80 can be combined with“plugging” devices and methods, systems and devices that approximate theleaflets 38, 42 and the annulus 84. For example, the coils that arelocated under the annulus 84 could be combined with a plugging oroccluding device that is positioned on the coil in the region of thecommisure 80.

Referring now to FIGS. 34J-34L, an alternative embodiment of a helicalanchor 650 in accordance with the present invention is shown. Asgenerally noted above, helical anchor 650 includes a covering 650 a,which may be a tissue in growth surface such as a covering (fabric, forexample) or coating or sleeve, or simply a surface treatment. Any of theoptions discussed herein may be used for purposes of improving theimplantation process and/or the quality of the implantationpost-procedure. FIG. 34J shows a helical anchor 650 having one turn 652above the mitral valve 44 in the left atrium 46, where it compressesagainst the atrial wall 46 a close to the valve 44. Two turns 654, 656sit under the leaflets 38, 42 and press upward against the leaflets tobring the margins of the anterior and posterior leaflets 38, 42 togetherto close the commisures 80 as shown in FIG. 34K. This preventspara-valve leaks once the prosthetic mitral valve is anchored.Additional coils around the perimeter of the helical anchor 650 ensurethat a valve prosthesis will be positioned in the center of the anchor650. It should be noted that this is particularly advantageous when avalve prosthesis is substantially smaller than a patient's native mitralvalve annulus 84, since the valve prosthesis could otherwise slip fromwithin the anchor and become dislodged. Before insertion into the mitralposition, the helical anchor 650 can sit flat in one plane. Therefore,after it is implanted there is a spring force exerted by the anchor 650pushing the mitral leaflets 38, 42 upward and together. In anotherembodiment even greater spring force can be applied if the anchor 650 isconstructed so that before insertion into the mitral position, the twoturns 654, 656 that sit under the annulus 84 are arranged to naturallyposition higher than the turn or coil 652 shown above the leaflets 38,42. During insertion, the coils 654, 656 will be directed first tospiral into the ventricle 10 and around the chords 48, then the finalcoil or coils 652 will be delivered onto an upper side of the valve 44.Because the lower coils 654, 656 will move toward their normal position(which is above coil 652), there will be a compressive force applied bycoils 654, 656 upwardly as viewed in FIG. 34J. FIG. 34L is a crosssection taken along line 34L-34L of FIG. 34K showing the upward forceexerted by the lower coils 654, 656 on the mitral leaflets 38, 42. Aportion of a second coil 660 of the anchor above the annulus 84 isshown.

Appendix A is attached and forms a part of this specification. AppendixA is a catalogue of Prototypes 1 through 8 that illustrate examples ofhelical anchors constructed in accordance with embodiments of theinvention and used for mitral valve prosthesis docking as describedherein. Each prototype helical anchor is represented by respective topand side view photographs as well as a diagrammatic side cross-sectionalview of the helical coil configuration relative to anterior andposterior mitral valve leaflets (represented by downwardly curved lines)after implantation.

In other embodiments involving a helical anchor, alternativeconfigurations may be used in accordance with the invention. Forexample, some of the coils of the helical anchor above the leaflets 38,42 may be placed in contact with the leaflets 38, 42 and some of thecoils of the helical anchor above the leaflets 38, 42 may be placed incontact with the atrial wall 46 a. The number of coils and the order ofcontact could vary. For example, coils may alternate between contactingthe leaflets 38, 42 and contacting the atrial wall 46 a. Alternatively,some of the coils of the helical anchor above the leaflets may retain avalve prosthesis without contacting the leaflets 38, 42 and some of thecoils above the leaflets 38, 42 may be placed in contact with the atrialwall. The coils that contact the atrial wall 46 a could pass eitherupward away from the mitral valve 44 or downward to contact the atrialwall 46 a proximate the mitral valve 44. In one embodiment the coils maypass downward such that they contact the outside of the coils whichretain the valve prosthesis, forming a double-coil. Advantages of adouble coil include improved structural strength of the helical anchorand decreased risk of thrombogenicity or embolization of the coils.

In further embodiments involving a helical anchor, the coils of theanchor can be carriers for an occluder device. For example, a pledget offabric or an Amplatzer devies could be threaded on the coils and movedto any position where a leak is possible. Occluding materials could alsobe positioned between coils. The previously described devices, systemsand methods for approximating the anterior and posterior leaflets 38, 42together may be used in conjunction with such occluding to provideimproved leak resistance.

In other embodiments, devices and systems as described can be introducedusing an open heart or puncture approach from the atrium 46, ventricle10 or aorta 18 or from catheters delivered into the left atrium 46 orretrograde from the aortic valve 22 into the left ventricle 10.Likewise, the system could be introduced in an open chest into theatrium 46 or percutaneously via the apex 6 with an apical occluder.Alternatively, introduction may be by way of other means, for example,through a min-incision in the heart 14 and/or endoscope.

Additionally, devices and systems as described can be introduced usingan approach in part or completely via the aorta 18. A coil guidecatheter or delivery catheter can be fed from any peripheral location(such as the groin, the shoulder region or the arm/wrist) or a centralaortic location to the aortic valve 22. All of these entry approachesare used commonly clinically for approaching the aortic valve 22 andcoronary arteries. The coil guide catheter or delivery catheter can thenbe fed across the aortic valve 22 into the left ventricle 10. Any of thepreviously described devices, systems and methods may then be employedto implant a mitral valve prosthesis using an approach from the leftventricle 10. Assisting tools described herein (e.g. snare catheter,grasping tool, etc.) may also be introduced via the aorta 18. Any routeof helical anchor or stent dock delivery (e.g. transseptal,transventricular, transaortic) can be used in conjunction with any routeof valve prosthesis delivery (e.g. transseptal, transventricular,transaortic).

In one embodiment, the grasping tool may be connected by a suture orthread to the end of the helical anchor. The suture or thread maycomprise a plastic material such as polypropylene which is commonly usedin sutures, or another synthetic material like polyester which isfrequently braided into sutures. The suture joins the grasping tool tothe end of the helical anchor by sliding through an aperture in thegrasping tool and leading it to the end of the anchor. At the end of theprocedure, the suture may be cut. The grasping tool may have integratedscissors for this purpose or the suture may be sheared with a separatetool. In another embodiment, the suture could be wrapped over the end ofthe helical anchor and tugged for release. The end of the helicalanchor, preferably characterized by an enlarged ball shape, may comprisean aperture for the suture to pass through, wherein the suture may beretained by crimping or gluing. After the procedure the suture could becut or tugged out. A useful maneuver to remove the suture with agrasping tool is to slide the grasping tool over the suture so that itis sitting at the end of the ball. The grasping tool is then rotated tojerk the suture from the inside of the ball so that it can be removed.It may also be desirable to avoid a rigid connection or link between thegrasping tool and the end of the helical anchor and avoid the use of asuture. Instead, a joint that pivots such as a universal joint may bedesirable.

There are some important dimensions to consider for the coil guidecatheter. The first dimension is the distance between the distal tip ofthe guide and the stem or straight part of the guide. This distance canbe constructed to be approximately equal to the diameter of the mitralannulus or the distance between the commisures so that when the stem ofthe coil guide catheter is directed through one commisure, the distaltip of the coil guide catheter will rest at the other commisure. Thismeans that the grasping tool will also pass through the mitral valve atthe commisure opposite to the stem so that the system is centered insidethe valve. It also provides a clear orientation for the starting pointof the anchor delivery with respect to the mitral valve leaflets. Thetip of the coil guide catheter is close to the commisure to ensure thatthe commisure receives the start of the helical anchor. The commisuresof the mitral valve are relatively easy to identify on echocardiographyso that the stem of the coil guide catheter and the grasping tool canthus be identified to be passing through the opposite commisures of themitral valve. By using this anatomic landmark, the operator will be ableto be sure that he or she is pushing the helical anchor under the mitralvalve leaflet at the commisure. This simple relationship can make itrelatively easy for the correct placement of the anchor. If the stem andthe grasping tool do not pass through the commisure, the coil guidecatheter can be rotated until they do. It is appreciated that theorientation does not have to be at the commisures. Any point along thevalve can be chosen, but the commisures are particularly easy toidentify with non-invasive imaging. If the operator desires to introducethe anchor at a point different from the commisure, the position of thestem and the grasping tool in relation to the mitral valve annulus canbe compared to the valve to precisely position the entry point of theanchor.

Another important dimension for the coil guide catheter is the distancefrom the widest point of the curve to a line joining the tip of the coilguide catheter to the distal end of the stem of the coil guide catheter.This dimension can be adjusted so that the curved part of the coil guide(which generally or roughly follows the path of the mitral annulus, sitsbeyond the end of the native mitral valve on the base of the heart. Anoperator can then place the coil guide catheter in position inside theheart at the commisures with echocardiographic guidance and then pullback on the coil guide catheter until it sits flush against the leftatrial wall. This provides tactile positioning to the operator andallows the depth of the coil guide catheter to be precisely adjusted.Visually, for example of fluoroscopy or echocardiography, the stoppingcan be recognized with a slight movement of the coil guide catheter asit hits against the atrial wall. As there is a slight upward curve ofthe left atrium as it passes away from the native mitral valve, a curveupward in the coil guide catheter over this curved part may be useful totrack the shape of the heart.

While the present invention has been illustrated by a description ofpreferred embodiments and while these embodiments have been described insome detail, it is not the intention of the Applicants to restrict or inany way limit the scope of the appended claims to such detail.Additional advantages and modifications will readily appear to thoseskilled in the art. The various features and concepts of the inventionmay be used alone or in any combination depending on the needs andpreferences of the operator. This has been a description of the presentinvention, along with the preferred methods of practicing the presentinvention as currently known. However, the invention itself should onlybe defined by the appended claims. What is claimed is:

1. A helical anchor for docking a mitral valve prosthesis, the helicalanchor adapted to be received in and delivered from a coil guidecatheter, and comprising: a plurality of coils having a preformed,coiled configuration after being delivered from the coil guide catheterand adapted to support the prosthetic mitral valve upon being fullydelivered from the coil guide catheter and implanted with respectivecoil portions above and below the mitral valve annulus, wherein thehelical anchor includes a distal end portion and the distal end portionis formed to extend downward and radially outward relative to a nextadjacent coil such that the distal end portion is spaced from the nextadjacent coil and is configured to be delivered between the commissuresof the native mitral valve.
 2. The helical anchor of claim 1, whereinthe plurality of coils includes a proximal end portion formed as anenlarged diameter coil relative to the next adjacent coil, the proximalend portion configured to engage the left atrial wall of the heart whenthe plurality of coils have been fully delivered from the coil guidecatheter with the respective coil portions above and below the mitralvalve annulus.
 3. The helical anchor of claim 1, further comprising aplurality of anchoring arms coupled with at least one of the pluralityof coils and configured to engage the mitral valve leaflets.
 4. Thehelical anchor of claim 1, wherein the helical anchor comprises a solidwire.
 5. The helical anchor of claim 1, wherein the helical anchorfurther comprises a hollow wire configured to be delivered over a guidewire.
 6. A system comprising: a prosthetic heart valve that is radiallyexpandable; an anchor for docking the prosthetic heart valve, thehelical anchor comprising a plurality of helical coils transitionable toa straightened configuration to be held in a catheter, wherein theplurality of helical coils are adapted to support the prosthetic heartvalve upon being fully delivered from the catheter at a native heartvalve and implanted with respective portions above and below a nativeheart valve annulus of the native heart valve, wherein the plurality ofhelical coils include a lower portion comprising a plurality of lowercoils and an upper portion, wherein the upper portion is adapted to beplaced above the native heart valve annulus and wherein the plurality oflower coils are configured to encircle heart valve leaflets of thenative heart valve and are configured such that, when the prostheticheart valve is docked within the anchor, the heart valve leaflets of thenative heart valve are secured between the plurality of lower coils andthe prosthetic heart valve, such that the anchor and the prostheticheart valve are locked in place relative to the heart valve leaflets,wherein the anchor includes a distal end portion and the distal endportion is formed to extend radially outward relative to a next adjacentcoil such that the distal end portion is spaced from the next adjacentcoil and is configured to be delivered between commissures of the nativeheart valve.
 7. The system of claim 6, wherein the catheter includes astem portion and a distal portion connected to the stem portion at afirst curved shape, the distal portion having a second curved shapeconfigured to generally follow the curvature of the native valveannulus, said first and second curved portions capable of beingdelivered in straightened configurations and activated to the first andsecond curved shapes within the heart proximate the native heart valve.8. The system of claim 7, further comprising an extension coupled withthe distal portion and configured to assist with positioning of thesecond curved shape on top of the native heart valve as the anchor isbeing delivered.
 9. The system of claim 6, wherein the prosthetic heartvalve is capable of being delivered to the native heart valve in acollapsed configuration and then expanded inside the plurality of lowercoils and into engagement with the heart valve leaflets of the nativeheart valve.
 10. The system of claim 6, further comprising a controlcatheter having connecting element configured to couple with the anchorfor guiding the placement of the anchor relative to the mitral valve,wherein the control catheter is reversibly coupleable to the anchor viaa suture.
 11. The system of claim 6, wherein the upper portion of theanchor comprises an extension portion configured to engage the wall ofan atrium and provide stabilization upon implantation in the heart. 12.The system of claim 6, wherein the upper portion of the anchor isadapted to be placed above the native heart valve annulus and extendupwardly to adjustably position the prosthetic heart valve at a desiredheight relative to the native heart valve annulus.
 13. The system ofclaim 6, wherein the plurality of lower coils are configured to containnative mitral valve leaflets therein and prevent obstruction of anaortic valve by an anterior mitral leaflet.
 14. The system of claim 6,wherein a distal tip at the distal end portion is blunt.
 15. A systemcomprising: a prosthetic heart valve that is radially expandable from acollapsed configuration to an expanded configuration; an anchor fordocking the prosthetic heart valve, the anchor adapted to be held in acatheter in an elongated configuration and delivered from the catheter,and the anchor configured to have a plurality of lower coils after beingdelivered from the catheter and adapted to support the prosthetic heartvalve upon being fully delivered from the catheter and implanted at anative heart valve; wherein the plurality of lower coils includes adistal end portion and the distal end portion is formed to extendradially outward relative to a next adjacent coil such that the distalend portion has a larger radius of curvature than the next adjacent coiland is configured to help direct the plurality of lower coils betweencommissures of the native heart valve and around native leaflets of thenative heart valve; and wherein the plurality of lower coils is adaptedto be placed below a native heart valve annulus of the native heartvalve such that the plurality of lower coils encircle the nativeleaflets and, when the prosthetic heart valve is docked within theanchor, the native leaflets are secured between the plurality of lowercoils and the prosthetic heart valve.
 16. The system of claim 15,wherein plurality of coils are configured such that the prosthetic heartvalve can be adjustably positioned at a desired height relative to thenative heart valve annulus.
 17. The system of claim 15, wherein thenative leaflets are native mitral valve leaflets of a native mitralvalve and wherein the plurality of lower coils are configured toencircle the native mitral valve leaflets such that an anterior leafletis prevented from obstructing of a native aortic valve.
 18. The systemof claim 15, wherein a proximal portion of the anchor is spaced apartfrom native heart valve leaflet tissue of the native heart valve uponimplantation.
 19. The system of claim 15, wherein multiple coils of theplurality of lower coils have the same diameter.
 20. A systemcomprising: a heart valve prosthesis that is radially expandable from acollapsed configuration to an expanded configuration, wherein the heartvalve prosthesis includes a plurality of tissue leaflets; a deliverycatheter having a distal portion transitionable into a curved shape; ananchor for docking the heart valve prosthesis, the anchor adapted to beheld in the delivery catheter in an elongated configuration anddelivered from the delivery catheter, and the anchor configured to havea plurality of lower coils after being delivered from the catheteradapted to support the heart valve prosthesis upon being fully deliveredfrom the catheter and implanted at a native mitral valve; wherein theplurality of lower coils includes a distal end portion and the distalend portion is formed to extend radially outward relative to a nextadjacent coil such that the distal end portion is has a larger radius ofcurvature than the next adjacent coil and is configured to help directthe plurality of lower coils between commissures of the native mitralvalve and around native leaflets of the native mitral valve; and whereinthe plurality of lower coils is adapted to be placed below a nativemitral annulus of the native mitral valve such that the plurality oflower coils encircle the native leaflets and, when the heart valveprosthesis is docked within the anchor, the native leaflets are securedbetween an inner surface of the plurality of lower coils and an outersurface of the heart valve prosthesis.